Surgical stapler having motor control based on an electrical parameter related to a motor current

ABSTRACT

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system is electrically connected to the electric motor and includes an H-bridge circuit, an electrically resistive element and an electrically inductive element. The H-bridge circuit includes a high side and a low side. The low side of the H-bridge circuit includes first and second switching devices. The electrically resistive element is electrically connected in series with the first switching device. The electrically inductive element is electrically connected to the electrically resistive element. The control system is configured to control a force applied to the drive system based on a current downstream of the electrically resistive element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application claiming priority under35 U.S.C. § 120 to U.S. patent application Ser. No. 16/146,772, entitledSURGICAL STAPLER HAVING MOTOR CONTROL BASED ON AN ELECTRICAL PARAMETERRELATED TO A MOTOR CURRENT, filed Sep. 28, 2018, now U.S. PatentApplication Publication No. 2019/0117216, which is a continuationapplication claiming priority under 35 U.S.C. § 120 to U.S. patentapplication Ser. No. 14/862,465, entitled SURGICAL STAPLER HAVING MOTORCONTROL BASED ON AN ELECTRICAL PARAMETER RELATED TO A MOTOR CURRENT,filed Sep. 23, 2015, now U.S. Pat. No. 10,238,386, the entiredisclosures of which are hereby incorporated by reference herein.

BACKGROUND

The invention disclosed herein relates to surgical instruments and, invarious embodiments, to surgical stapling and cutting instruments andstaple cartridges for use therewith.

A stapling instrument can include a pair of cooperating elongate jawmembers, wherein each jaw member can be adapted to be inserted into apatient and positioned relative to tissue that is to be stapled and/orincised. In various embodiments, one of the jaw members can support astaple cartridge with at least two laterally spaced rows of staplescontained therein, and the other jaw member can support an anvil withstaple-forming pockets aligned with the rows of staples in the staplecartridge. Generally, the stapling instrument can further include apusher bar and a knife blade which are slidable relative to the jawmembers to sequentially eject the staples from the staple cartridge viacamming surfaces on the pusher bar and/or camming surfaces on a wedgesled that is pushed by the pusher bar. In at least one embodiment, thecamming surfaces can be configured to activate a plurality of stapledrivers carried by the cartridge and associated with the staples inorder to push the staples against the anvil and form laterally spacedrows of deformed staples in the tissue gripped between the jaw members.In at least one embodiment, the knife blade can trail the cammingsurfaces and cut the tissue along a line between the staple rows.

The foregoing discussion is intended only to illustrate various aspectsof the related art in the field of the invention at the time, and shouldnot be taken as a disavowal of claim scope.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the embodiments described herein, together withadvantages thereof, may be understood in accordance with the followingdescription taken in conjunction with the accompanying drawings asfollows:

FIG. 1 is a perspective view of a surgical instrument that has aninterchangeable shaft assembly operably coupled thereto;

FIG. 2 is an exploded assembly view of the interchangeable shaftassembly and surgical instrument of FIG. 1;

FIG. 3 is another exploded assembly view showing portions of theinterchangeable shaft assembly and surgical instrument of FIGS. 1 and 2;

FIG. 4 is an exploded assembly view of a portion of the surgicalinstrument of FIGS. 1-3;

FIG. 5 is a cross-sectional side view of a portion of the surgicalinstrument of FIG. 4 with the firing trigger in a fully actuatedposition;

FIG. 6 is another cross-sectional view of a portion of the surgicalinstrument of FIG. 5 with the firing trigger in an unactuated position;

FIG. 7 is an exploded assembly view of one form of an interchangeableshaft assembly;

FIG. 8 is another exploded assembly view of portions of theinterchangeable shaft assembly of FIG. 7;

FIG. 9 is another exploded assembly view of portions of theinterchangeable shaft assembly of FIGS. 7 and 8;

FIG. 10 is a cross-sectional view of a portion of the interchangeableshaft assembly of FIGS. 7-9;

FIG. 11 is a perspective view of a portion of the shaft assembly ofFIGS. 7-10 with the switch drum omitted for clarity;

FIG. 12 is another perspective view of the portion of theinterchangeable shaft assembly of FIG. 11 with the switch drum mountedthereon;

FIG. 13 is a perspective view of a portion of the interchangeable shaftassembly of FIG. 11 operably coupled to a portion of the surgicalinstrument of FIG. 1 illustrated with the closure trigger thereof in anunactuated position;

FIG. 14 is a right side elevational view of the interchangeable shaftassembly and surgical instrument of FIG. 13;

FIG. 15 is a left side elevational view of the interchangeable shaftassembly and surgical instrument of FIGS. 13 and 14;

FIG. 16 is a perspective view of a portion of the interchangeable shaftassembly of FIG. 11 operably coupled to a portion of the surgicalinstrument of FIG. 1 illustrated with the closure trigger thereof in anactuated position and a firing trigger thereof in an unactuatedposition;

FIG. 17 is a right side elevational view of the interchangeable shaftassembly and surgical instrument of FIG. 16;

FIG. 18 is a left side elevational view of the interchangeable shaftassembly and surgical instrument of FIGS. 16 and 17;

FIG. 18A is a right side elevational view of the interchangeable shaftassembly of FIG. 11 operably coupled to a portion of the surgicalinstrument of FIG. 1 illustrated with the closure trigger thereof in anactuated position and the firing trigger thereof in an actuatedposition;

FIG. 19 is a schematic of a system for powering down an electricalconnector of a surgical instrument handle when a shaft assembly is notcoupled thereto;

FIG. 20 is an exploded view of one aspect of an end effector of thesurgical instrument of FIG. 1;

FIGS. 21A-21B is a circuit diagram of the surgical instrument of FIG. 1spanning two drawings sheets;

FIG. 21A is a first portion of a circuit diagram of the surgicalinstrument of FIG. 1;

FIG. 21B is a second portion of the circuit diagram of FIG. 21A;

FIG. 22 illustrates one instance of a power assembly comprising a usagecycle circuit configured to generate a usage cycle count of the batteryback;

FIG. 23 illustrates one aspect of a process for sequentially energizinga segmented circuit;

FIG. 24 illustrates one aspect of a power segment comprising a pluralityof daisy chained power converters;

FIG. 25 illustrates one aspect of a segmented circuit configured tomaximize power available for critical and/or power intense functions;

FIG. 26 illustrates one aspect of a power system comprising a pluralityof daisy chained power converters configured to be sequentiallyenergized;

FIG. 27 illustrates one aspect of a segmented circuit comprising anisolated control section;

FIGS. 28A-28B is a circuit diagram of the surgical instrument of FIG. 1spanning two drawing sheets;

FIG. 28A is a first portion of a circuit diagram of the surgicalinstrument of FIG. 1;

FIG. 28B is a second portion of the circuit diagram of FIG. 28A;

FIG. 29 is a block diagram the surgical instrument of FIG. 1illustrating interfaces between the handle assembly 14 and the powerassembly and between the handle assembly 14 and the interchangeableshaft assembly;

FIG. 30 illustrates a simplified representation of various embodimentsof a surgical stapler;

FIG. 31 illustrates a simplified representation of various embodimentsof a surgical stapler;

FIG. 32 illustrates a simplified representation of various embodimentsof a surgical stapler;

FIG. 33 illustrates exemplary battery current and recirculation currentwaveforms of a surgical stapler according to various embodiments; and

FIG. 34 illustrates an exemplary sampling of a battery current ofvarious embodiments of a surgical stapler over multiple periods of a PWMduty cycle.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate various embodiments of the invention, in one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

Applicant of the present application owns the following patentapplications that were filed on Sep. 23, 2015 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/862,415, entitled SURGICAL STAPLERHAVING DOWNSTREAM CURRENT-BASED MOTOR CONTROL, now U.S. Pat. No.10,105,139;

U.S. patent application Ser. No. 14/862,421, entitled SURGICAL STAPLERHAVING MOTOR CONTROL BASED ON A DRIVE SYSTEM COMPONENT, now U.S. Pat.No. 10,327,769;

U.S. patent application Ser. No. 14/862,427, entitled SURGICAL STAPLERHAVING TEMPERATURE-BASED MOTOR CONTROL, now U.S. Pat. No. 10,085,751;

U.S. patent application Ser. No. 14/862,434, entitled SURGICAL STAPLERHAVING MAGNETIC FIELD-BASED MOTOR CONTROL, now U.S. Patent ApplicationPublication No. 2017/0079642;

U.S. patent application Ser. No. 14/862,439, entitled SURGICAL STAPLERHAVING FORCE-BASED MOTOR CONTROL, now U.S. Pat. No. 10,363,036; and

U.S. patent application Ser. No. 14/862,455, entitled SURGICAL STAPLERHAVING CURRENT MIRROR-BASED MOTOR CONTROL, now U.S. Pat. No. 10,076,326.

Applicant of the present application owns the following patentapplications that were filed on Mar. 6, 2015 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/640,746, entitled POWERED SURGICALINSTRUMENT, now U.S. Pat. No. 9,808,246;

U.S. patent application Ser. No. 14/640,765, entitled SYSTEM FORDETECTING THE MIS-INSERTION OF A STAPLE CARTRIDGE INTO A SURGICALSTAPLER, now U.S. Pat. No. 10,617,412;

U.S. patent application Ser. No. 14/640,780, entitled SURGICALINSTRUMENT COMPRISING A LOCKABLE BATTERY HOUSING, now U.S. Pat. No.10,245,033;

U.S. patent application Ser. No. 14/640,795, entitled MULTIPLE LEVELTHRESHOLDS TO MODIFY OPERATION OF POWERED SURGICAL INSTRUMENTS, now U.S.Pat. No. 10,441,279;

U.S. patent application Ser. No. 14/640,799, entitled SIGNAL AND POWERCOMMUNICATION SYSTEM POSITIONED ON A ROTATABLE SHAFT, now U.S. Pat. No.9,901,342;

U.S. patent application Ser. No. 14/640,817, entitled INTERACTIVEFEEDBACK SYSTEM FOR POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No.9,924,961;

U.S. patent application Ser. No. 14/640,831, entitled MONITORING SPEEDCONTROL AND PRECISION INCREMENTING OF MOTOR FOR POWERED SURGICALINSTRUMENTS, now U.S. Pat. No. 9,895,148;

U.S. patent application Ser. No. 14/640,832, entitled ADAPTIVE TISSUECOMPRESSION TECHNIQUES TO ADJUST CLOSURE RATES FOR MULTIPLE TISSUETYPES, now U.S. Pat. No. 10,687,806;

U.S. patent application Ser. No. 14/640,837, entitled SMART SENSORS WITHLOCAL SIGNAL PROCESSING, now U.S. Pat. No. 9,993,248;

U.S. patent application Ser. No. 14/640,844, entitled CONTROL TECHNIQUESAND SUB-PROCESSOR CONTAINED WITHIN MODULAR SHAFT WITH SELECT CONTROLPROCESSING FROM HANDLE, now U.S. Pat. No. 10,045,776;

U.S. patent application Ser. No. 14/640,859, entitled TIME DEPENDENTEVALUATION OF SENSOR DATA TO DETERMINE STABILITY, CREEP, ANDVISCOELASTIC ELEMENTS OF MEASURES, now U.S. Pat. No. 10,052,044; and

U.S. patent application Ser. No. 14/640,935, entitled OVERLAID MULTISENSOR RADIO FREQUENCY (RF) ELECTRODE SYSTEM TO MEASURE TISSUECOMPRESSION, now U.S. Pat. No. 10,548,504.

Applicant of the present application owns the following patentapplications that were filed on Feb. 27, 2015, and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/633,526, entitled ADAPTABLE SURGICALINSTRUMENT HANDLE, now U.S. Pat. No. 9,993,258;

U.S. patent application Ser. No. 14/633,541, entitled MODULAR STAPLINGASSEMBLY, now U.S. Pat. No. 10,226,250;

U.S. patent application Ser. No. 14/633,542, entitled REINFORCED BATTERYFOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,931,118;

U.S. patent application Ser. No. 14/633,546, entitled SURGICAL APPARATUSCONFIGURED TO ASSESS WHETHER A PERFORMANCE PARAMETER OF THE SURGICALAPPARATUS IS WITHIN AN ACCEPTABLE PERFORMANCE BAND, now U.S. Pat. No.10,180,463;

U.S. patent application Ser. No. 14/633,548, entitled POWER ADAPTER FORA SURGICAL INSTRUMENT, now U.S. Pat. No. 10,245,028;

U.S. patent application Ser. No. 14/633,555, entitled SYSTEM FORMONITORING WHETHER A SURGICAL INSTRUMENT NEEDS TO BE SERVICED, now U.S.Pat. No. 10,321,907;

U.S. patent application Ser. No. 14/633,560, entitled SURGICAL CHARGINGSYSTEM THAT CHARGES AND/OR CONDITIONS ONE OR MORE BATTERIES, now U.S.Patent Application Publication No. 2016/0249910;

U.S. patent application Ser. No. 14/633,562, entitled SURGICAL APPARATUSCONFIGURED TO TRACK AN END-OF-LIFE PARAMETER, now U.S. Pat. No.10,159,4863;

U.S. patent application Ser. No. 14/633,566, entitled CHARGING SYSTEMTHAT ENABLES EMERGENCY RESOLUTIONS FOR CHARGING A BATTERY, now U.S. Pat.No. 10,182,816; and

U.S. patent application Ser. No. 14/633,576, entitled SURGICALINSTRUMENT SYSTEM COMPRISING AN INSPECTION STATION, now U.S. Pat. No.10,045,779.

Applicant of the present application owns the following patentapplications that were filed on Dec. 18, 2014 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/574,478, entitled SURGICALINSTRUMENT SYSTEMS COMPRISING AN ARTICULATABLE END EFFECTOR AND MEANSFOR ADJUSTING THE FIRING STROKE OF A FIRING, now U.S. Pat. No.9,844,374;

U.S. patent application Ser. No. 14/574,483, entitled SURGICALINSTRUMENT ASSEMBLY COMPRISING LOCKABLE SYSTEMS, now U.S. Pat. No.10,188,385;

U.S. patent application Ser. No. 14/574,493, entitled SURGICALINSTRUMENT ASSEMBLY COMPRISING A FLEXIBLE ARTICULATION SYSTEM, now U.S.Pat. No. 9,987,000;

U.S. patent application Ser. No. 14/574,500, entitled SURGICALINSTRUMENT ASSEMBLY COMPRISING A LOCKABLE ARTICULATION SYSTEM, now U.S.Pat. No. 10,117,649;

U.S. patent application Ser. No. 14/575,117, entitled SURGICALINSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND MOVABLE FIRING BEAMSUPPORT ARRANGEMENTS, now U.S. Pat. No. 9,943,309;

U.S. patent application Ser. No. 14/575,130, entitled SURGICALINSTRUMENT WITH AN ANVIL THAT IS SELECTIVELY MOVABLE ABOUT A DISCRETENON-MOVABLE AXIS RELATIVE TO A STAPLE CARTRIDGE, now U.S. Pat. No.10,245,027;

U.S. patent application Ser. No. 14/575,139, entitled DRIVE ARRANGEMENTSFOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,844,375;

U.S. patent application Ser. No. 14/575,143, entitled SURGICALINSTRUMENTS WITH IMPROVED CLOSURE ARRANGEMENTS, now U.S. Pat. No.10,004,501;

U.S. patent application Ser. No. 14/575,148, entitled LOCKINGARRANGEMENTS FOR DETACHABLE SHAFT ASSEMBLIES WITH ARTICULATABLE SURGICALEND EFFECTORS, now U.S. Pat. No. 10,085,748; and

U.S. patent application Ser. No. 14/575,154, entitled SURGICALINSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND IMPROVED FIRING BEAMSUPPORT ARRANGEMENTS, now U.S. Pat. No. 9,968,355.

Applicant of the present application also owns the following patentapplications that were filed on Sep. 5, 2014 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/478,895, entitled MULTIPLE SENSORSWITH ONE SENSOR AFFECTING A SECOND SENSOR'S OUTPUT OR INTERPRETATION,now U.S. Pat. No. 9,757,128;

U.S. patent application Ser. No. 14/478,908, entitled MONITORING DEVICEDEGRADATION BASED ON COMPONENT EVALUATION, now U.S. Pat. No. 9,737,301;

U.S. patent application Ser. No. 14/479,098, entitled SMART CARTRIDGEWAKE UP OPERATION AND DATA RETENTION, now U.S. Pat. No. 10,135,242;

U.S. patent application Ser. No. 14/479,103, entitled CIRCUITRY ANDSENSORS FOR POWERED MEDICAL DEVICE, now U.S. Pat. No. 10,111,679;

U.S. patent application Ser. No. 14/479,108, entitled LOCAL DISPLAY OFTISSUE PARAMETER STABILIZATION, now U.S. Patent Application PublicationNo. 2016/0066913;

U.S. patent application Ser. No. 14/479,110, entitled USE OF POLARITY OFHALL MAGNET DETECTION TO DETECT MISLOADED CARTRIDGE, now U.S. Pat. No.10,016,199;

U.S. patent application Ser. No. 14/479,115, entitled MULTIPLE MOTORCONTROL FOR POWERED MEDICAL DEVICE, now U.S. Pat. No. 9,788,836; and

U.S. patent application Ser. No. 14/479,119, entitled ADJUNCT WITHINTEGRATED SENSORS TO QUANTIFY TISSUE COMPRESSION, now U.S. Pat. No.9,724,094.

Applicant of the present application also owns the following patentapplications that were filed on Apr. 9, 2014 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/248,581, entitled SURGICALINSTRUMENT COMPRISING A CLOSING DRIVE AND A FIRING DRIVE OPERATED FROMTHE SAME ROTATABLE OUTPUT, now U.S. Pat. No. 9,649,110;

U.S. patent application Ser. No. 14/248,584, entitled MODULAR MOTORDRIVEN SURGICAL INSTRUMENTS WITH ALIGNMENT FEATURES FOR ALIGNING ROTARYDRIVE SHAFTS WITH SURGICAL END EFFECTOR SHAFTS, now U.S. Pat. No.9,801,626;

U.S. patent application Ser. No. 14/248,586, entitled DRIVE SYSTEMDECOUPLING ARRANGEMENT FORA SURGICAL INSTRUMENT, now U.S. Pat. No.10,136,887;

U.S. patent application Ser. No. 14/248,587, entitled POWERED SURGICALSTAPLER, now U.S. Pat. No. 9,867,612;

U.S. patent application Ser. No. 14/248,588, entitled POWERED LINEARSURGICAL STAPLER, now U.S. Pat. No. 10,405,857;

U.S. patent application Ser. No. 14/248,590, entitled MOTOR DRIVENSURGICAL INSTRUMENTS WITH LOCKABLE DUAL DRIVE SHAFTS, now U.S. Pat. No.9,826,976;

U.S. patent application Ser. No. 14/248,591, entitled TRANSMISSIONARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 10,149,680;

U.S. patent application Ser. No. 14/248,595, entitled SURGICALINSTRUMENT SHAFT INCLUDING SWITCHES FOR CONTROLLING THE OPERATION OF THESURGICAL INSTRUMENT, now U.S. Pat. No. 9,844,368; and

U.S. patent application Ser. No. 14/248,607, entitled MODULAR MOTORDRIVEN SURGICAL INSTRUMENTS WITH STATUS INDICATION ARRANGEMENTS, nowU.S. Pat. No. 9,814,460.

Applicant of the present application also owns the following patentapplications that were filed on Mar. 26, 2014 and are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 14/226,071, entitled SURGICALINSTRUMENT CONTROL CIRCUIT HAVING A SAFETY PROCESSOR, now U.S. Pat. No.9,690,362;

U.S. patent application Ser. No. 14/226,075, entitled MODULAR POWEREDSURGICAL INSTRUMENT WITH DETACHABLE SHAFT ASSEMBLIES, now U.S. Pat. No.9,743,929;

U.S. patent application Ser. No. 14/226,076, entitled POWER MANAGEMENTTHROUGH SEGMENTED CIRCUIT AND VARIABLE VOLTAGE PROTECTION, now U.S. Pat.No. 9,733,663;

U.S. patent application Ser. No. 14/226,081, entitled SYSTEMS ANDMETHODS FOR CONTROLLING A SEGMENTED CIRCUIT, now U.S. Pat. No.9,804,618;

U.S. patent application Ser. No. 14/226,093, entitled FEEDBACKALGORITHMS FOR MANUAL BAILOUT SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S.Pat. No. 10,028,761;

U.S. patent application Ser. No. 14/226,094, entitled VERIFICATION OFNUMBER OF BATTERY EXCHANGES/PROCEDURE COUNT, now U.S. Patent ApplicationPublication No. 2015/0272580;

U.S. patent application Ser. No. 14/226,097, entitled SURGICALINSTRUMENT COMPRISING INTERACTIVE SYSTEMS, now U.S. Pat. No. 9,820,738;

U.S. patent application Ser. No. 14/226,099, entitled STERILIZATIONVERIFICATION CIRCUIT, now U.S. Pat. No. 9,826,977;

U.S. patent application Ser. No. 14/226,106, entitled POWER MANAGEMENTCONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent ApplicationPublication No. 2015/0272582;

U.S. patent application Ser. No. 14/226,111, entitled SURGICAL STAPLINGINSTRUMENT SYSTEM, now U.S. Pat. No. 9,750,499;

U.S. patent application Ser. No. 14/226,116, entitled SURGICALINSTRUMENT UTILIZING SENSOR ADAPTATION, now U.S. Patent ApplicationPublication No. 2015/0272571;

U.S. patent application Ser. No. 14/226,117, entitled POWER MANAGEMENTTHROUGH SLEEP OPTIONS OF SEGMENTED CIRCUIT AND WAKE UP CONTROL, now U.S.Pat. No. 10,013,049;

U.S. patent application Ser. No. 14/226,125, entitled SURGICALINSTRUMENT COMPRISING A ROTATABLE SHAFT, now U.S. Pat. No. 10,201,364;

U.S. patent application Ser. No. 14/226,126, entitled INTERFACE SYSTEMSFOR USE WITH SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,004,497; and

U.S. patent application Ser. No. 14/226,133, entitled MODULAR SURGICALINSTRUMENT SYSTEM, now U.S. Patent Application Publication No.2015/0272557.

Applicant of the present application also owns the following patentapplication that was filed on Mar. 7, 2014 and is herein incorporated byreference in its entirety:

U.S. patent application Ser. No. 14/200,111, entitled CONTROL SYSTEMSFOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,629,629.

Applicant of the present application also owns the following patentapplications that were filed on Apr. 16, 2013 and which are each hereinincorporated by reference in their respective entireties:

U.S. Provisional Patent Application Ser. No. 61/812,365, entitledSURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;

U.S. Provisional Patent Application Ser. No. 61/812,372, entitledSURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;

U.S. Provisional Patent Application Ser. No. 61/812,376, entitled LINEARCUTTER WITH POWER;

U.S. Provisional Patent Application Ser. No. 61/812,382, entitled LINEARCUTTER WITH MOTOR AND PISTOL GRIP; and

U.S. Provisional Patent Application Ser. No. 61/812,385, entitledSURGICAL INSTRUMENT HANDLE WITH MULTIPLE ACTUATION MOTORS AND MOTORCONTROL.

Applicant of the present application also owns the following patentapplications that were filed on Mar. 14, 2013 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 13/803,053, entitled INTERCHANGEABLESHAFT ASSEMBLIES FOR USE WITH A SURGICAL INSTRUMENT, now U.S. Pat. No.9,883,860;

U.S. patent application Ser. No. 13/803,066, entitled DRIVE SYSTEMLOCKOUT ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No.9,629,623;

U.S. patent application Ser. No. 13/803,086, entitled ARTICULATABLESURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. PatentApplication Publication No. 2014/0263541;

U.S. patent application Ser. No. 13/803,097, entitled ARTICULATABLESURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, now U.S. Pat. No.9,687,230;

U.S. patent application Ser. No. 13/803,117, entitled ARTICULATIONCONTROL SYSTEM FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No.9,351,726;

U.S. patent application Ser. No. 13/803,130, entitled DRIVE TRAINCONTROL ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No.9,351,727;

U.S. patent application Ser. No. 13/803,148, entitled MULTI-FUNCTIONMOTOR FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,351,727;

U.S. patent application Ser. No. 13/803,159, entitled METHOD AND SYSTEMFOR OPERATING A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,888,919;

U.S. patent application Ser. No. 13/803,193, entitled CONTROLARRANGEMENTS FOR A DRIVE MEMBER OF A SURGICAL INSTRUMENT, now U.S. Pat.No. 9,332,987; and

U.S. patent application Ser. No. 13/803,210, entitled SENSORARRANGEMENTS FOR ABSOLUTE POSITIONING SYSTEM FOR SURGICAL INSTRUMENTS,now U.S. Pat. No. 9,808,244.

Applicant of the present application owns the following patentapplications that were filed on Mar. 1, 2013 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 13/782,295, entitled ARTICULATABLESURGICAL INSTRUMENTS WITH CONDUCTIVE PATHWAYS FOR SIGNAL COMMUNICATION,now U.S. Pat. No. 9,700,309;

U.S. patent application Ser. No. 13/782,323, entitled ROTARY POWEREDARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No.9,782,169;

U.S. patent application Ser. No. 13/782,338, entitled THUMBWHEEL SWITCHARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent ApplicationPublication No. 2014/0249557;

U.S. patent application Ser. No. 13/782,358, entitled JOYSTICK SWITCHASSEMBLIES FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,326,767;

U.S. patent application Ser. No. 13/782,375, entitled ROTARY POWEREDSURGICAL INSTRUMENTS WITH MULTIPLE DEGREES OF FREEDOM, now U.S. Pat. No.9,398,911;

U.S. patent application Ser. No. 13/782,460, entitled MULTIPLE PROCESSORMOTOR CONTROL FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No.9,554,794;

U.S. patent application Ser. No. 13/782,481, entitled SENSORSTRAIGHTENED END EFFECTOR DURING REMOVAL THROUGH TROCAR, now U.S. Pat.No. 9,468,438;

U.S. patent application Ser. No. 13/782,499, entitled ELECTROMECHANICALSURGICAL DEVICE WITH SIGNAL RELAY ARRANGEMENT, now U.S. Pat. No.9,358,003;

U.S. patent application Ser. No. 13/782,518, entitled CONTROL METHODSFOR SURGICAL INSTRUMENTS WITH REMOVABLE IMPLEMENT PORTIONS, now U.S.Patent Application Publication No. 2014/0246475; and

U.S. patent application Ser. No. 13/782,536, entitled SURGICALINSTRUMENT SOFT STOP, now U.S. Pat. No. 9,307,986.

Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. Well-known operations, components, andelements have not been described in detail so as not to obscure theembodiments described in the specification. The reader will understandthat the embodiments described and illustrated herein are non-limitingexamples, and thus it can be appreciated that the specific structuraland functional details disclosed herein may be representative andillustrative. Variations and changes thereto may be made withoutdeparting from the scope of the claims.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), “include” (and any form of include, such as “includes” and“including”) and “contain” (and any form of contain, such as “contains”and “containing”) are open-ended linking verbs. As a result, a surgicalsystem, device, or apparatus that “comprises,” “has,” “includes” or“contains” one or more elements possesses those one or more elements,but is not limited to possessing only those one or more elements.Likewise, an element of a system, device, or apparatus that “comprises,”“has,” “includes” or “contains” one or more features possesses those oneor more features, but is not limited to possessing only those one ormore features.

The terms “proximal” and “distal” are used herein with reference to aclinician manipulating the handle portion of the surgical instrument.The term “proximal” referring to the portion closest to the clinicianand the term “distal” referring to the portion located away from theclinician. It will be further appreciated that, for convenience andclarity, spatial terms such as “vertical”, “horizontal”, “up”, and“down” may be used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performinglaparoscopic and minimally invasive surgical procedures. However, thereader will readily appreciate that the various methods and devicesdisclosed herein can be used in numerous surgical procedures andapplications including, for example, in connection with open surgicalprocedures. As the present Detailed Description proceeds, the readerwill further appreciate that the various instruments disclosed hereincan be inserted into a body in any way, such as through a naturalorifice, through an incision or puncture hole formed in tissue, etc. Theworking portions or end effector portions of the instruments can beinserted directly into a patient's body or can be inserted through anaccess device that has a working channel through which the end effectorand elongated shaft of a surgical instrument can be advanced.

A surgical stapling system can comprise a shaft and an end effectorextending from the shaft. The end effector comprises a first jaw and asecond jaw. The first jaw comprises a staple cartridge. The staplecartridge is insertable into and removable from the first jaw; however,other embodiments are envisioned in which a staple cartridge is notremovable from, or at least readily replaceable from, the first jaw. Thesecond jaw comprises an anvil configured to deform staples ejected fromthe staple cartridge. The second jaw is pivotable relative to the firstjaw about a closure axis; however, other embodiments are envisioned inwhich first jaw is pivotable relative to the second jaw. The surgicalstapling system further comprises an articulation joint configured topermit the end effector to be rotated, or articulated, relative to theshaft. The end effector is rotatable about an articulation axisextending through the articulation joint. Other embodiments areenvisioned which do not include an articulation joint.

The staple cartridge comprises a cartridge body. The cartridge bodyincludes a proximal end, a distal end, and a deck extending between theproximal end and the distal end. In use, the staple cartridge ispositioned on a first side of the tissue to be stapled and the anvil ispositioned on a second side of the tissue. The anvil is moved toward thestaple cartridge to compress and clamp the tissue against the deck.Thereafter, staples removably stored in the cartridge body can bedeployed into the tissue. The cartridge body includes staple cavitiesdefined therein wherein staples are removably stored in the staplecavities. The staple cavities are arranged in six longitudinal rows.Three rows of staple cavities are positioned on a first side of alongitudinal slot and three rows of staple cavities are positioned on asecond side of the longitudinal slot. Other arrangements of staplecavities and staples may be possible.

The staples are supported by staple drivers in the cartridge body. Thedrivers are movable between a first, or unfired position, and a second,or fired, position to eject the staples from the staple cavities. Thedrivers are retained in the cartridge body by a retainer which extendsaround the bottom of the cartridge body and includes resilient membersconfigured to grip the cartridge body and hold the retainer to thecartridge body. The drivers are movable between their unfired positionsand their fired positions by a sled. The sled is movable between aproximal position adjacent the proximal end and a distal positionadjacent the distal end. The sled comprises a plurality of rampedsurfaces configured to slide under the drivers and lift the drivers, andthe staples supported thereon, toward the anvil.

Further to the above, the sled is moved distally by a firing member. Thefiring member is configured to contact the sled and push the sled towardthe distal end. The longitudinal slot defined in the cartridge body isconfigured to receive the firing member. The anvil also includes a slotconfigured to receive the firing member. The firing member furthercomprises a first cam which engages the first jaw and a second cam whichengages the second jaw. As the firing member is advanced distally, thefirst cam and the second cam can control the distance, or tissue gap,between the deck of the staple cartridge and the anvil. The firingmember also comprises a knife configured to incise the tissue capturedintermediate the staple cartridge and the anvil. It is desirable for theknife to be positioned at least partially proximal to the rampedsurfaces such that the staples are ejected ahead of the knife.

FIGS. 1-6 depict a motor-driven surgical cutting and fasteninginstrument 10 that may or may not be reused. In the illustratedexamples, the instrument 10 includes a housing 12 that comprises ahandle assembly 14 that is configured to be grasped, manipulated andactuated by the clinician. The housing 12 is configured for operableattachment to an interchangeable shaft assembly 200 that has a surgicalend effector 300 operably coupled thereto that is configured to performone or more surgical tasks or procedures. As the present DetailedDescription proceeds, it will be understood that the various unique andnovel arrangements of the various forms of interchangeable shaftassemblies disclosed herein also may be effectively employed inconnection with robotically-controlled surgical systems. Thus, the term“housing” also may encompass a housing or similar portion of a roboticsystem that houses or otherwise operably supports at least one drivesystem that is configured to generate and apply at least one controlmotion which could be used to actuate the interchangeable shaftassemblies disclosed herein and their respective equivalents. The term“frame” may refer to a portion of a handheld surgical instrument. Theterm “frame” also may represent a portion of a robotically controlledsurgical instrument and/or a portion of the robotic system that may beused to operably control a surgical instrument. For example, theinterchangeable shaft assemblies disclosed herein may be employed withvarious robotic systems, instruments, components and methods disclosedin U.S. patent application Ser. No. 13/118,241, entitled SURGICALSTAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, nowU.S. Pat. No. 9,072,535. U.S. patent application Ser. No. 13/118,241,entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENTARRANGEMENTS, now U.S. Pat. No. 9,072,535, is incorporated by referenceherein in its entirety.

The housing 12 depicted in FIGS. 1-3 is shown in connection with aninterchangeable shaft assembly 200 that includes an end effector 300that comprises a surgical cutting and fastening device that isconfigured to operably support a surgical staple cartridge 304 therein.The housing 12 may be configured for use in connection withinterchangeable shaft assemblies that include end effectors that areadapted to support different sizes and types of staple cartridges, havedifferent shaft lengths, sizes, and types, etc. In addition, the housing12 also may be effectively employed with a variety of otherinterchangeable shaft assemblies including those assemblies that areconfigured to apply other motions and forms of energy such as, forexample, radio frequency (RF) energy, ultrasonic energy and/or motion toend effector arrangements adapted for use in connection with varioussurgical applications and procedures. Furthermore, the end effectors,shaft assemblies, handles, surgical instruments, and/or surgicalinstrument systems can utilize any suitable fastener, or fasteners, tofasten tissue. For instance, a fastener cartridge comprising a pluralityof fasteners removably stored therein can be removably inserted intoand/or attached to the end effector of a shaft assembly.

FIG. 1 illustrates the surgical instrument 10 with an interchangeableshaft assembly 200 operably coupled thereto. FIGS. 2 and 3 illustrateattachment of the interchangeable shaft assembly 200 to the housing 12or handle assembly 14. As shown in FIG. 4, the handle assembly 14 maycomprise a pair of interconnectable handle housing segments 16 and 18that may be interconnected by screws, snap features, adhesive, etc. Inthe illustrated arrangement, the handle housing segments 16, 18cooperate to form a pistol grip portion 19 that can be gripped andmanipulated by the clinician. As will be discussed in further detailbelow, the handle assembly 14 operably supports a plurality of drivesystems therein that are configured to generate and apply variouscontrol motions to corresponding portions of the interchangeable shaftassembly that is operably attached thereto.

Referring now to FIG. 4, the handle assembly 14 may further include aframe 20 that operably supports a plurality of drive systems. Forexample, the frame 20 can operably support a “first” or closure drivesystem, generally designated as 30, which may be employed to applyclosing and opening motions to the interchangeable shaft assembly 200that is operably attached or coupled thereto. In at least one form, theclosure drive system 30 may include an actuator in the form of a closuretrigger 32 that is pivotally supported by the frame 20. Morespecifically, as illustrated in FIG. 4, the closure trigger 32 ispivotally coupled to the housing 14 by a pin 33. Such arrangementenables the closure trigger 32 to be manipulated by a clinician suchthat when the clinician grips the pistol grip portion 19 of the handleassembly 14, the closure trigger 32 may be easily pivoted from astarting or “unactuated” position to an “actuated” position and moreparticularly to a fully compressed or fully actuated position. Theclosure trigger 32 may be biased into the unactuated position by springor other biasing arrangement (not shown). In various forms, the closuredrive system 30 further includes a closure linkage assembly 34 that ispivotally coupled to the closure trigger 32. As shown in FIG. 4, theclosure linkage assembly 34 may include a first closure link 36 and asecond closure link 38 that are pivotally coupled to the closure trigger32 by a pin 35. The second closure link 38 also may be referred toherein as an “attachment member” and include a transverse attachment pin37.

Still referring to FIG. 4, it can be observed that the first closurelink 36 may have a locking wall or end 39 thereon that is configured tocooperate with a closure release assembly 60 that is pivotally coupledto the frame 20. In at least one form, the closure release assembly 60may comprise a release button assembly 62 that has a distally protrudinglocking pawl 64 formed thereon. The release button assembly 62 may bepivoted in a counterclockwise direction by a release spring (not shown).As the clinician depresses the closure trigger 32 from its unactuatedposition towards the pistol grip portion 19 of the handle assembly 14,the first closure link 36 pivots upward to a point wherein the lockingpawl 64 drops into retaining engagement with the locking wall 39 on thefirst closure link 36 thereby preventing the closure trigger 32 fromreturning to the unactuated position. See FIG. 18. Thus, the closurerelease assembly 60 serves to lock the closure trigger 32 in the fullyactuated position. When the clinician desires to unlock the closuretrigger 32 to permit it to be biased to the unactuated position, theclinician simply pivots the closure release button assembly 62 such thatthe locking pawl 64 is moved out of engagement with the locking wall 39on the first closure link 36. When the locking pawl 64 has been movedout of engagement with the first closure link 36, the closure trigger 32may pivot back to the unactuated position. Other closure trigger lockingand release arrangements also may be employed.

Further to the above, FIGS. 13-15 illustrate the closure trigger 32 inits unactuated position which is associated with an open, or unclamped,configuration of the shaft assembly 200 in which tissue can bepositioned between the jaws of the shaft assembly 200. FIGS. 16-18illustrate the closure trigger 32 in its actuated position which isassociated with a closed, or clamped, configuration of the shaftassembly 200 in which tissue is clamped between the jaws of the shaftassembly 200. Upon comparing FIGS. 14 and 17, the reader will appreciatethat, when the closure trigger 32 is moved from its unactuated position(FIG. 14) to its actuated position (FIG. 17), the closure release button62 is pivoted between a first position (FIG. 14) and a second position(FIG. 17). The rotation of the closure release button 62 can be referredto as being an upward rotation; however, at least a portion of theclosure release button 62 is being rotated toward the circuit board 100.Referring to FIG. 4, the closure release button 62 can include an arm 61extending therefrom and a magnetic element 63, such as a permanentmagnet, for example, mounted to the arm 61. When the closure releasebutton 62 is rotated from its first position to its second position, themagnetic element 63 can move toward the circuit board 100. The circuitboard 100 can include at least one sensor configured to detect themovement of the magnetic element 63. In at least one aspect, a magneticfield sensor 65, for example, can be mounted to the bottom surface ofthe circuit board 100. The magnetic field sensor 65 can be configured todetect changes in a magnetic field surrounding the magnetic field sensor65 caused by the movement of the magnetic element 63. The magnetic fieldsensor 65 can be in signal communication with a microcontroller 1500(FIG. 19), for example, which can determine whether the closure releasebutton 62 is in its first position, which is associated with theunactuated position of the closure trigger 32 and the open configurationof the end effector, its second position, which is associated with theactuated position of the closure trigger 32 and the closed configurationof the end effector, and/or any position between the first position andthe second position.

As used throughout the present disclosure, a magnetic field sensor maybe a Hall effect sensor, search coil, fluxgate, optically pumped,nuclear precession, SQUID, Hall-effect, anisotropic magnetoresistance,giant magnetoresistance, magnetic tunnel junctions, giantmagnetoimpedance, magnetostrictive/piezoelectric composites,magnetodiode, magnetotransistor, fiber optic, magnetooptic, andmicroelectromechanical systems-based magnetic sensors, among others.

In at least one form, the handle assembly 14 and the frame 20 mayoperably support another drive system referred to herein as a firingdrive system 80 that is configured to apply firing motions tocorresponding portions of the interchangeable shaft assembly attachedthereto. The firing drive system may 80 also be referred to herein as a“second drive system”. The firing drive system 80 may employ an electricmotor 82, located in the pistol grip portion 19 of the handle assembly14. In various forms, the motor 82 may be a DC brushed driving motorhaving a maximum rotation of, approximately, 25,000 RPM, for example. Inother arrangements, the motor 82 may include a brushless motor, acordless motor, a synchronous motor, a stepper motor, or any othersuitable electric motor. The motor 82 may be powered by a power source90 that in one form may comprise a removable power pack 92. As shown inFIG. 4, for example, the power pack 92 may comprise a proximal housingportion 94 that is configured for attachment to a distal housing portion96. The proximal housing portion 94 and the distal housing portion 96are configured to operably support a plurality of batteries 98 therein.Batteries 98 may each comprise, for example, a Lithium Ion (“LI”) orother suitable battery. The distal housing portion 96 is configured forremovable operable attachment to a control circuit board assembly 100which is also operably coupled to the motor 82. A number of batteries 98may be connected in series may be used as the power source for thesurgical instrument 10. In addition, the power source 90 may bereplaceable and/or rechargeable.

As outlined above with respect to other various forms, the electricmotor 82 can include a rotatable shaft (not shown) that operablyinterfaces with a gear reducer assembly 84 that is mounted in meshingengagement with a with a set, or rack, of drive teeth 122 on alongitudinally-movable drive member 120. In use, a voltage polarityprovided by the power source 90 can operate the electric motor 82 in aclockwise direction wherein the voltage polarity applied to the electricmotor by the battery can be reversed in order to operate the electricmotor 82 in a counter-clockwise direction. When the electric motor 82 isrotated in one direction, the drive member 120 will be axially driven inthe distal direction “DD”. When the motor 82 is driven in the oppositerotary direction, the drive member 120 will be axially driven in aproximal direction “PD”. The handle assembly 14 can include a switchwhich can be configured to reverse the polarity applied to the electricmotor 82 by the power source 90. As with the other forms describedherein, the handle assembly 14 can also include a sensor that isconfigured to detect the position of the drive member 120 and/or thedirection in which the drive member 120 is being moved.

Actuation of the motor 82 can be controlled by a firing trigger 130 thatis pivotally supported on the handle assembly 14. The firing trigger 130may be pivoted between an unactuated position and an actuated position.The firing trigger 130 may be biased into the unactuated position by aspring 132 or other biasing arrangement such that when the clinicianreleases the firing trigger 130, it may be pivoted or otherwise returnedto the unactuated position by the spring 132 or biasing arrangement. Inat least one form, the firing trigger 130 can be positioned “outboard”of the closure trigger 32 as was discussed above. In at least one form,a firing trigger safety button 134 may be pivotally mounted to theclosure trigger 32 by pin 35. The safety button 134 may be positionedbetween the firing trigger 130 and the closure trigger 32 and have apivot arm 136 protruding therefrom. See FIG. 4. When the closure trigger32 is in the unactuated position, the safety button 134 is contained inthe handle assembly 14 where the clinician cannot readily access it andmove it between a safety position preventing actuation of the firingtrigger 130 and a firing position wherein the firing trigger 130 may befired. As the clinician depresses the closure trigger 32, the safetybutton 134 and the firing trigger 130 pivot down wherein they can thenbe manipulated by the clinician.

As discussed above, the handle assembly 14 can include a closure trigger32 and a firing trigger 130. Referring to FIGS. 14-18A, the firingtrigger 130 can be pivotably mounted to the closure trigger 32. Theclosure trigger 32 can include an arm 31 extending therefrom and thefiring trigger 130 can be pivotably mounted to the arm 31 about a pivotpin 33. When the closure trigger 32 is moved from its unactuatedposition (FIG. 14) to its actuated position (FIG. 17), the firingtrigger 130 can descend downwardly, as outlined above. After the safetybutton 134 has been moved to its firing position, referring primarily toFIG. 18A, the firing trigger 130 can be depressed to operate the motorof the surgical instrument firing system. In various instances, thehandle assembly 14 can include a tracking system, such as system 800,for example, configured to determine the position of the closure trigger32 and/or the position of the firing trigger 130. With primary referenceto FIGS. 14, 17, and 18A, the tracking system 800 can include a magneticelement, such as permanent magnet 802, for example, which is mounted toan arm 801 extending from the firing trigger 130. The tracking system800 can comprise one or more sensors, such as a first magnetic fieldsensor 803 and a second magnetic field sensor 804, for example, whichcan be configured to track the position of the magnet 802.

Upon comparing FIGS. 14 and 17, the reader will appreciate that, whenthe closure trigger 32 is moved from its unactuated position to itsactuated position, the magnet 802 can move between a first positionadjacent the first magnetic field sensor 803 and a second positionadjacent the second magnetic field sensor 804.

Upon comparing FIGS. 17 and 18A, the reader will further appreciatethat, when the firing trigger 130 is moved from an unfired position(FIG. 17) to a fired position (FIG. 18A), the magnet 802 can moverelative to the second magnetic field sensor 804. The sensors 803 and804 can track the movement of the magnet 802 and can be in signalcommunication with a microcontroller on the circuit board 100. With datafrom the first sensor 803 and/or the second sensor 804, themicrocontroller can determine the position of the magnet 802 along apredefined path and, based on that position, the microcontroller candetermine whether the closure trigger 32 is in its unactuated position,its actuated position, or a position therebetween. Similarly, with datafrom the first sensor 803 and/or the second sensor 804, themicrocontroller can determine the position of the magnet 802 along apredefined path and, based on that position, the microcontroller candetermine whether the firing trigger 130 is in its unfired position, itsfully fired position, or a position therebetween.

As indicated above, in at least one form, the longitudinally movabledrive member 120 has a rack of teeth 122 formed thereon for meshingengagement with a corresponding drive gear 86 of the gear reducerassembly 84. At least one form also includes a manually-actuatable“bailout” assembly 140 that is configured to enable the clinician tomanually retract the longitudinally movable drive member 120 should themotor 82 become disabled. The bailout assembly 140 may include a leveror bailout handle assembly 142 that is configured to be manually pivotedinto ratcheting engagement with teeth 124 also provided in the drivemember 120. Thus, the clinician can manually retract the drive member120 by using the bailout handle assembly 142 to ratchet the drive member120 in the proximal direction “PD”. U.S. Patent Application PublicationNo. 2010/0089970, now U.S. Pat. No. 8,608,045, discloses bailoutarrangements and other components, arrangements and systems that alsomay be employed with the various instruments disclosed herein. U.S.patent application Ser. No. 12/249,117, entitled POWERED SURGICALCUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM,U.S. Patent Application Publication No. 2010/0089970, now U.S. Pat. No.8,608,045, is hereby incorporated by reference in its entirety.

Turning now to FIGS. 1 and 7, the interchangeable shaft assembly 200includes a surgical end effector 300 that comprises an elongated channel302 that is configured to operably support a staple cartridge 304therein. The end effector 300 may further include an anvil 306 that ispivotally supported relative to the elongated channel 302. Theinterchangeable shaft assembly 200 may further include an articulationjoint 270 and an articulation lock 350 (FIG. 8) which can be configuredto releasably hold the end effector 300 in a desired position relativeto a shaft axis SA-SA. Details regarding the construction and operationof the end effector 300, the articulation joint 270 and the articulationlock 350 are set forth in U.S. patent application Ser. No. 13/803,086,filed Mar. 14, 2013, entitled ARTICULATABLE SURGICAL INSTRUMENTCOMPRISING AN ARTICULATION LOCK, now U.S. Patent Application PublicationNo. 2014/0263541. The entire disclosure of U.S. patent application Ser.No. 13/803,086, filed Mar. 14, 2013, entitled ARTICULATABLE SURGICALINSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent ApplicationPublication No. 2014/0263541, is hereby incorporated by referenceherein. As shown in FIGS. 7 and 8, the interchangeable shaft assembly200 can further include a proximal housing or nozzle 201 comprised ofnozzle portions 202 and 203. The interchangeable shaft assembly 200 canfurther include a closure tube 260 which can be utilized to close and/oropen the anvil 306 of the end effector 300. Primarily referring now toFIGS. 8 and 9, the shaft assembly 200 can include a spine 210 which canbe configured to fixably support a shaft frame portion 212 of thearticulation lock 350. See FIG. 8. The spine 210 can be configured to,one, slidably support a firing member 220 therein and, two, slidablysupport the closure tube 260 which extends around the spine 210. Thespine 210 can also be configured to slidably support a proximalarticulation driver 230. The articulation driver 230 has a distal end231 that is configured to operably engage the articulation lock 350. Thearticulation lock 350 interfaces with an articulation frame 352 that isadapted to operably engage a drive pin (not shown) on the end effectorframe (not shown). As indicated above, further details regarding theoperation of the articulation lock 350 and the articulation frame may befound in U.S. patent application Ser. No. 13/803,086, now U.S. PatentApplication Publication No. 2014/0263541. In various circumstances, thespine 210 can comprise a proximal end 211 which is rotatably supportedin a chassis 240. In one arrangement, for example, the proximal end 211of the spine 210 has a thread 214 formed thereon for threaded attachmentto a spine bearing 216 configured to be supported within the chassis240. See FIG. 7. Such an arrangement facilitates rotatable attachment ofthe spine 210 to the chassis 240 such that the spine 210 may beselectively rotated about a shaft axis SA-SA relative to the chassis240.

Referring primarily to FIG. 7, the interchangeable shaft assembly 200includes a closure shuttle 250 that is slidably supported within thechassis 240 such that it may be axially moved relative thereto. As shownin FIGS. 3 and 7, the closure shuttle 250 includes a pair ofproximally-protruding hooks 252 that are configured for attachment tothe attachment pin 37 that is attached to the second closure link 38 aswill be discussed in further detail below. A proximal end 261 of theclosure tube 260 is coupled to the closure shuttle 250 for relativerotation thereto. For example, a U shaped connector 263 is inserted intoan annular slot 262 in the proximal end 261 of the closure tube 260 andis retained within vertical slots 253 in the closure shuttle 250. SeeFIG. 7. Such an arrangement serves to attach the closure tube 260 to theclosure shuttle 250 for axial travel therewith while enabling theclosure tube 260 to rotate relative to the closure shuttle 250 about theshaft axis SA-SA. A closure spring 268 is journaled on the closure tube260 and serves to bias the closure tube 260 in the proximal direction“PD” which can serve to pivot the closure trigger into the unactuatedposition when the shaft assembly is operably coupled to the handleassembly 14.

In at least one form, the interchangeable shaft assembly 200 may furtherinclude an articulation joint 270. Other interchangeable shaftassemblies, however, may not be capable of articulation. As shown inFIG. 7, for example, the articulation joint 270 includes a double pivotclosure sleeve assembly 271. According to various forms, the doublepivot closure sleeve assembly 271 includes an end effector closuresleeve assembly 272 having upper and lower distally projecting tangs273, 274. An end effector closure sleeve assembly 272 includes ahorseshoe aperture 275 and a tab 276 for engaging an opening tab on theanvil 306 in the various manners described in U.S. patent applicationSer. No. 13/803,086, filed Mar. 14, 2013, entitled ARTICULATABLESURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. PatentApplication Publication No. 2014/0263541, which has been incorporated byreference herein. As described in further detail therein, the horseshoeaperture 275 and tab 276 engage a tab on the anvil when the anvil 306 isopened. An upper double pivot link 277 includes upwardly projectingdistal and proximal pivot pins that engage respectively an upper distalpin hole in the upper proximally projecting tang 273 and an upperproximal pin hole in an upper distally projecting tang 264 on theclosure tube 260. A lower double pivot link 278 includes upwardlyprojecting distal and proximal pivot pins that engage respectively alower distal pin hole in the lower proximally projecting tang 274 and alower proximal pin hole in the lower distally projecting tang 265. Seealso FIG. 8.

In use, the closure tube 260 is translated distally (direction “DD”) toclose the anvil 306, for example, in response to the actuation of theclosure trigger 32. The anvil 306 is closed by distally translating theclosure tube 260 and thus the shaft closure sleeve assembly 272, causingit to strike a proximal surface on the anvil 360 in the manner describedin the aforementioned reference U.S. patent application Ser. No.13/803,086, now U.S. Patent Application Publication No. 2014/0263541. Aswas also described in detail in that reference, the anvil 306 is openedby proximally translating the closure tube 260 and the shaft closuresleeve assembly 272, causing tab 276 and the horseshoe aperture 275 tocontact and push against the anvil tab to lift the anvil 306. In theanvil-open position, the shaft closure tube 260 is moved to its proximalposition.

As indicated above, the surgical instrument 10 may further include anarticulation lock 350 of the types and construction described in furtherdetail in U.S. patent application Ser. No. 13/803,086, now U.S. PatentApplication Publication No. 2014/0263541, which can be configured andoperated to selectively lock the end effector 300 in position. Sucharrangement enables the end effector 300 to be rotated, or articulated,relative to the shaft closure tube 260 when the articulation lock 350 isin its unlocked state. In such an unlocked state, the end effector 300can be positioned and pushed against soft tissue and/or bone, forexample, surrounding the surgical site within the patient in order tocause the end effector 300 to articulate relative to the closure tube260. The end effector 300 also may be articulated relative to theclosure tube 260 by an articulation driver 230.

As was also indicated above, the interchangeable shaft assembly 200further includes a firing member 220 that is supported for axial travelwithin the shaft spine 210. The firing member 220 includes anintermediate firing shaft portion 222 that is configured for attachmentto a distal cutting portion or knife bar 280. The firing member 220 alsomay be referred to herein as a “second shaft” and/or a “second shaftassembly”. As shown in FIGS. 8 and 9, the intermediate firing shaftportion 222 may include a longitudinal slot 223 in the distal endthereof which can be configured to receive a tab 284 on the proximal end282 of the distal knife bar 280. The longitudinal slot 223 and theproximal end 282 can be sized and configured to permit relative movementtherebetween and can comprise a slip joint 286. The slip joint 286 canpermit the intermediate firing shaft portion 222 of the firing drive 220to be moved to articulate the end effector 300 without moving, or atleast substantially moving, the knife bar 280. Once the end effector 300has been suitably oriented, the intermediate firing shaft portion 222can be advanced distally until a proximal sidewall of the longitudinalslot 223 comes into contact with the tab 284 in order to advance theknife bar 280 and fire the staple cartridge positioned within thechannel 302 As can be further seen in FIGS. 8 and 9, the shaft spine 210has an elongate opening or window 213 therein to facilitate assembly andinsertion of the intermediate firing shaft portion 222 into the shaftframe 210. Once the intermediate firing shaft portion 222 has beeninserted therein, a top frame segment 215 may be engaged with the shaftframe 212 to enclose the intermediate firing shaft portion 222 and knifebar 280 therein. Further description of the operation of the firingmember 220 may be found in U.S. patent application Ser. No. 13/803,086,now U.S. Patent Application Publication No. 2014/0263541.

Further to the above, the shaft assembly 200 can include a clutchassembly 400 which can be configured to selectively and releasablycouple the articulation driver 230 to the firing member 220. In oneform, the clutch assembly 400 includes a lock collar, or sleeve 402,positioned around the firing member 220 wherein the lock sleeve 402 canbe rotated between an engaged position in which the lock sleeve 402couples the articulation driver 360 to the firing member 220 and adisengaged position in which the articulation driver 360 is not operablycoupled to the firing member 200. When lock sleeve 402 is in its engagedposition, distal movement of the firing member 220 can move thearticulation driver 360 distally and, correspondingly, proximal movementof the firing member 220 can move the articulation driver 230proximally. When lock sleeve 402 is in its disengaged position, movementof the firing member 220 is not transmitted to the articulation driver230 and, as a result, the firing member 220 can move independently ofthe articulation driver 230. In various circumstances, the articulationdriver 230 can be held in position by the articulation lock 350 when thearticulation driver 230 is not being moved in the proximal or distaldirections by the firing member 220.

Referring primarily to FIG. 9, the lock sleeve 402 can comprise acylindrical, or an at least substantially cylindrical, body including alongitudinal aperture 403 defined therein configured to receive thefiring member 220. The lock sleeve 402 can comprisediametrically-opposed, inwardly-facing lock protrusions 404 and anoutwardly-facing lock member 406. The lock protrusions 404 can beconfigured to be selectively engaged with the firing member 220. Moreparticularly, when the lock sleeve 402 is in its engaged position, thelock protrusions 404 are positioned within a drive notch 224 defined inthe firing member 220 such that a distal pushing force and/or a proximalpulling force can be transmitted from the firing member 220 to the locksleeve 402. When the lock sleeve 402 is in its engaged position, thesecond lock member 406 is received within a drive notch 232 defined inthe articulation driver 230 such that the distal pushing force and/orthe proximal pulling force applied to the lock sleeve 402 can betransmitted to the articulation driver 230. In effect, the firing member220, the lock sleeve 402, and the articulation driver 230 will movetogether when the lock sleeve 402 is in its engaged position. On theother hand, when the lock sleeve 402 is in its disengaged position, thelock protrusions 404 may not be positioned within the drive notch 224 ofthe firing member 220 and, as a result, a distal pushing force and/or aproximal pulling force may not be transmitted from the firing member 220to the lock sleeve 402. Correspondingly, the distal pushing force and/orthe proximal pulling force may not be transmitted to the articulationdriver 230. In such circumstances, the firing member 220 can be slidproximally and/or distally relative to the lock sleeve 402 and theproximal articulation driver 230.

As shown in FIGS. 8-12, the shaft assembly 200 further includes a switchdrum 500 that is rotatably received on the closure tube 260. The switchdrum 500 comprises a hollow shaft segment 502 that has a shaft boss 504formed thereon for receive an outwardly protruding actuation pin 410therein. In various circumstances, the actuation pin 410 extends througha slot 267 into a longitudinal slot 408 provided in the lock sleeve 402to facilitate axial movement of the lock sleeve 402 when it is engagedwith the articulation driver 230. A rotary torsion spring 420 isconfigured to engage the boss 504 on the switch drum 500 and a portionof the nozzle housing 203 as shown in FIG. 10 to apply a biasing forceto the switch drum 500. The switch drum 500 can further comprise atleast partially circumferential openings 506 defined therein which,referring to FIGS. 5 and 6, can be configured to receive circumferentialmounts 204, 205 extending from the nozzle halves 202, 203 and permitrelative rotation, but not translation, between the switch drum 500 andthe proximal nozzle 201. As shown in those Figures, the mounts 204 and205 also extend through openings 266 in the closure tube 260 to beseated in recesses 209 in the shaft spine 210. However, rotation of thenozzle 201 to a point where the mounts 204, 205 reach the end of theirrespective slots 506 in the switch drum 500 will result in rotation ofthe switch drum 500 about the shaft axis SA-SA. Rotation of the switchdrum 500 will ultimately result in the rotation of the actuation pin 410and the lock sleeve 402 between its engaged and disengaged positions.Thus, in essence, the nozzle 201 may be employed to operably engage anddisengage the articulation drive system with the firing drive system inthe various manners described in further detail in U.S. patentapplication Ser. No. 13/803,086, now U.S. Patent Application PublicationNo. 2014/0263541.

As also illustrated in FIGS. 8-12, the shaft assembly 200 can comprise aslip ring assembly 600 which can be configured to conduct electricalpower to and/or from the end effector 300 and/or communicate signals toand/or from the end effector 300, for example. The slip ring assembly600 can comprise a proximal connector flange 604 mounted to a chassisflange 242 extending from the chassis 240 and a distal connector flange601 positioned within a slot defined in the shaft housings 202, 203. Theproximal connector flange 604 can comprise a first face and the distalconnector flange 601 can comprise a second face which is positionedadjacent to and movable relative to the first face. The distal connectorflange 601 can rotate relative to the proximal connector flange 604about the shaft axis SA-SA. The proximal connector flange 604 cancomprise a plurality of concentric, or at least substantiallyconcentric, conductors 602 defined in the first face thereof. Aconnector 607 can be mounted on the proximal side of the connectorflange 601 and may have a plurality of contacts (not shown) wherein eachcontact corresponds to and is in electrical contact with one of theconductors 602. Such an arrangement permits relative rotation betweenthe proximal connector flange 604 and the distal connector flange 601while maintaining electrical contact therebetween. The proximalconnector flange 604 can include an electrical connector 606 which canplace the conductors 602 in signal communication with a shaft circuitboard 610 mounted to the shaft chassis 240, for example. In at least oneinstance, a wiring harness comprising a plurality of conductors canextend between the electrical connector 606 and the shaft circuit board610. The electrical connector 606 may extend proximally through aconnector opening 243 defined in the chassis mounting flange 242. SeeFIG. 7. U.S. patent application Ser. No. 13/800,067, entitled STAPLECARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, nowU.S. Patent Application Publication No. 2014/0263552, is incorporated byreference in its entirety. U.S. patent application Ser. No. 13/800,025,entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar.13, 2013, now U.S. Pat. No. 9,345,481, is incorporated by reference inits entirety. Further details regarding slip ring assembly 600 may befound in U.S. patent application Ser. No. 13/803,086, now U.S. PatentApplication Publication No. 2014/0263541.

As discussed above, the shaft assembly 200 can include a proximalportion which is fixably mounted to the handle assembly 14 and a distalportion which is rotatable about a longitudinal axis. The rotatabledistal shaft portion can be rotated relative to the proximal portionabout the slip ring assembly 600, as discussed above. The distalconnector flange 601 of the slip ring assembly 600 can be positionedwithin the rotatable distal shaft portion. Moreover, further to theabove, the switch drum 500 can also be positioned within the rotatabledistal shaft portion. When the rotatable distal shaft portion isrotated, the distal connector flange 601 and the switch drum 500 can berotated synchronously with one another. In addition, the switch drum 500can be rotated between a first position and a second position relativeto the distal connector flange 601. When the switch drum 500 is in itsfirst position, the articulation drive system may be operably disengagedfrom the firing drive system and, thus, the operation of the firingdrive system may not articulate the end effector 300 of the shaftassembly 200. When the switch drum 500 is in its second position, thearticulation drive system may be operably engaged with the firing drivesystem and, thus, the operation of the firing drive system mayarticulate the end effector 300 of the shaft assembly 200. When theswitch drum 500 is moved between its first position and its secondposition, the switch drum 500 is moved relative to distal connectorflange 601. In various instances, the shaft assembly 200 can comprise atleast one sensor configured to detect the position of the switch drum500. Turning now to FIGS. 11 and 12, the distal connector flange 601 cancomprise a magnetic field sensor 605, for example, and the switch drum500 can comprise a magnetic element, such as permanent magnet 505, forexample. The magnetic field sensor 605 can be configured to detect theposition of the permanent magnet 505. When the switch drum 500 isrotated between its first position and its second position, thepermanent magnet 505 can move relative to the magnetic field sensor 605.In various instances, magnetic field sensor 605 can detect changes in amagnetic field created when the permanent magnet 505 is moved. Themagnetic field sensor 605 can be in signal communication with the shaftcircuit board 610 and/or the handle circuit board 100, for example.Based on the signal from the magnetic field sensor 605, amicrocontroller on the shaft circuit board 610 and/or the handle circuitboard 100 can determine whether the articulation drive system is engagedwith or disengaged from the firing drive system.

Referring again to FIGS. 3 and 7, the chassis 240 includes at least one,and preferably two, tapered attachment portions 244 formed thereon thatare adapted to be received within corresponding dovetail slots 702formed within a distal attachment flange portion 700 of the frame 20.Each dovetail slot 702 may be tapered or, stated another way, besomewhat V-shaped to seatingly receive the attachment portions 244therein. As can be further seen in FIGS. 3 and 7, a shaft attachment lug226 is formed on the proximal end of the intermediate firing shaft 222.As will be discussed in further detail below, when the interchangeableshaft assembly 200 is coupled to the handle assembly 14, the shaftattachment lug 226 is received in a firing shaft attachment cradle 126formed in the distal end 125 of the longitudinal drive member 120 asshown in FIGS. 3 and 6, for example.

Various shaft assemblies employ a latch system 710 for removablycoupling the shaft assembly 200 to the housing 12 and more specificallyto the frame 20. As shown in FIG. 7, for example, in at least one form,the latch system 710 includes a lock member or lock yoke 712 that ismovably coupled to the chassis 240. In the illustrated example, forexample, the lock yoke 712 has a U-shape with two spaced downwardlyextending legs 714. The legs 714 each have a pivot lug 715 formedthereon that are adapted to be received in corresponding holes 245formed in the chassis 240. Such arrangement facilitates pivotalattachment of the lock yoke 712 to the chassis 240. The lock yoke 712may include two proximally protruding lock lugs 716 that are configuredfor releasable engagement with corresponding lock detents or grooves 704in the distal attachment flange 700 of the frame 20. See FIG. 3. Invarious forms, the lock yoke 712 is biased in the proximal direction byspring or biasing member (not shown). Actuation of the lock yoke 712 maybe accomplished by a latch button 722 that is slidably mounted on alatch actuator assembly 720 that is mounted to the chassis 240. Thelatch button 722 may be biased in a proximal direction relative to thelock yoke 712. As will be discussed in further detail below, the lockyoke 712 may be moved to an unlocked position by biasing the latchbutton the in distal direction which also causes the lock yoke 712 topivot out of retaining engagement with the distal attachment flange 700of the frame 20. When the lock yoke 712 is in “retaining engagement”with the distal attachment flange 700 of the frame 20, the lock lugs 716are retainingly seated within the corresponding lock detents or grooves704 in the distal attachment flange 700.

When employing an interchangeable shaft assembly that includes an endeffector of the type described herein that is adapted to cut and fastentissue, as well as other types of end effectors, it may be desirable toprevent inadvertent detachment of the interchangeable shaft assemblyfrom the housing during actuation of the end effector. For example, inuse the clinician may actuate the closure trigger 32 to grasp andmanipulate the target tissue into a desired position. Once the targettissue is positioned within the end effector 300 in a desiredorientation, the clinician may then fully actuate the closure trigger 32to close the anvil 306 and clamp the target tissue in position forcutting and stapling. In that instance, the first drive system 30 hasbeen fully actuated. After the target tissue has been clamped in the endeffector 300, it may be desirable to prevent the inadvertent detachmentof the shaft assembly 200 from the housing 12. One form of the latchsystem 710 is configured to prevent such inadvertent detachment.

As can be most particularly seen in FIG. 7, the lock yoke 712 includesat least one and preferably two lock hooks 718 that are adapted tocontact corresponding lock lug portions 256 that are formed on theclosure shuttle 250. Referring to FIGS. 13-15, when the closure shuttle250 is in an unactuated position (i.e., the first drive system 30 isunactuated and the anvil 306 is open), the lock yoke 712 may be pivotedin a distal direction to unlock the interchangeable shaft assembly 200from the housing 12. When in that position, the lock hooks 718 do notcontact the lock lug portions 256 on the closure shuttle 250. However,when the closure shuttle 250 is moved to an actuated position (i.e., thefirst drive system 30 is actuated and the anvil 306 is in the closedposition), the lock yoke 712 is prevented from being pivoted to anunlocked position. See FIGS. 16-18. Stated another way, if the clinicianwere to attempt to pivot the lock yoke 712 to an unlocked position or,for example, the lock yoke 712 was in advertently bumped or contacted ina manner that might otherwise cause it to pivot distally, the lock hooks718 on the lock yoke 712 will contact the lock lug portions 256 on theclosure shuttle 250 and prevent movement of the lock yoke 712 to anunlocked position.

Attachment of the interchangeable shaft assembly 200 to the handleassembly 14 will now be described with reference to FIG. 3. To commencethe coupling process, the clinician may position the chassis 240 of theinterchangeable shaft assembly 200 above or adjacent to the distalattachment flange 700 of the frame 20 such that the tapered attachmentportions 244 formed on the chassis 240 are aligned with the dovetailslots 702 in the frame 20. The clinician may then move the shaftassembly 200 along an installation axis IA that is perpendicular to theshaft axis SA-SA to seat the attachment portions 244 in “operableengagement” with the corresponding dovetail receiving slots 702. Indoing so, the shaft attachment lug 226 on the intermediate firing shaft222 will also be seated in the cradle 126 in the longitudinally movabledrive member 120 and the portions of pin 37 on the second closure link38 will be seated in the corresponding hooks 252 in the closure yoke250. As used herein, the term “operable engagement” in the context oftwo components means that the two components are sufficiently engagedwith each other so that upon application of an actuation motion thereto,the components may carry out their intended action, function and/orprocedure.

As discussed above, at least five systems of the interchangeable shaftassembly 200 can be operably coupled with at least five correspondingsystems of the handle assembly 14. A first system can comprise a framesystem which couples and/or aligns the frame or spine of the shaftassembly 200 with the frame 20 of the handle assembly 14. Another systemcan comprise a closure drive system 30 which can operably connect theclosure trigger 32 of the handle assembly 14 and the closure tube 260and the anvil 306 of the shaft assembly 200. As outlined above, theclosure tube attachment yoke 250 of the shaft assembly 200 can beengaged with the pin 37 on the second closure link 38. Another systemcan comprise the firing drive system 80 which can operably connect thefiring trigger 130 of the handle assembly 14 with the intermediatefiring shaft 222 of the shaft assembly 200.

As outlined above, the shaft attachment lug 226 can be operablyconnected with the cradle 126 of the longitudinal drive member 120.Another system can comprise an electrical system which can signal to acontroller in the handle assembly 14, such as microcontroller, forexample, that a shaft assembly, such as shaft assembly 200, for example,has been operably engaged with the handle assembly 14 and/or, two,conduct power and/or communication signals between the shaft assembly200 and the handle assembly 14. For instance, the shaft assembly 200 caninclude an electrical connector 1410 that is operably mounted to theshaft circuit board 610. The electrical connector 1410 is configured formating engagement with a corresponding electrical connector 1400 on thehandle control board 100. Further details regaining the circuitry andcontrol systems may be found in U.S. patent application Ser. No.13/803,086, now U.S. Patent Application Publication No. 2014/0263541,the entire disclosure of which was previously incorporated by referenceherein. The fifth system may consist of the latching system forreleasably locking the shaft assembly 200 to the handle assembly 14.

Referring again to FIGS. 2 and 3, the handle assembly 14 can include anelectrical connector 1400 comprising a plurality of electrical contacts.Turning now to FIG. 19, the electrical connector 1400 can comprise afirst contact 1401 a, a second contact 1401 b, a third contact 1401 c, afourth contact 1401 d, a fifth contact 1401 e, and a sixth contact 1401f, for example. While the illustrated example utilizes six contacts,other examples are envisioned which may utilize more than six contactsor less than six contacts.

As illustrated in FIG. 19, the first contact 1401 a can be in electricalcommunication with a transistor 1408, contacts 1401 b-1401 e can be inelectrical communication with a microcontroller 1500, and the sixthcontact 1401 f can be in electrical communication with a ground. Incertain circumstances, one or more of the electrical contacts 1401b-1401 e may be in electrical communication with one or more outputchannels of the microcontroller 1500 and can be energized, or have avoltage potential applied thereto, when the handle assembly 14 is in apowered state. In some circumstances, one or more of the electricalcontacts 1401 b-1401 e may be in electrical communication with one ormore input channels of the microcontroller 1500 and, when the handleassembly 14 is in a powered state, the microcontroller 1500 can beconfigured to detect when a voltage potential is applied to suchelectrical contacts. When a shaft assembly, such as shaft assembly 200,for example, is assembled to the handle assembly 14, the electricalcontacts 1401 a-1401 f may not communicate with each other. When a shaftassembly is not assembled to the handle assembly 14, however, theelectrical contacts 1401 a-1401 f of the electrical connector 1400 maybe exposed and, in some circumstances, one or more of the contacts 1401a-1401 f may be accidentally placed in electrical communication witheach other. Such circumstances can arise when one or more of thecontacts 1401 a-1401 f come into contact with an electrically conductivematerial, for example. When this occurs, the microcontroller 1500 canreceive an erroneous input and/or the shaft assembly 200 can receive anerroneous output, for example. To address this issue, in variouscircumstances, the handle assembly 14 may be unpowered when a shaftassembly, such as shaft assembly 200, for example, is not attached tothe handle assembly 14.

In other circumstances, the handle assembly 14 can be powered when ashaft assembly, such as shaft assembly 200, for example, is not attachedthereto. In such circumstances, the microcontroller 1500 can beconfigured to ignore inputs, or voltage potentials, applied to thecontacts in electrical communication with the microcontroller 1500,i.e., contacts 1401 b-1401 e, for example, until a shaft assembly isattached to the handle assembly 14. Even though the microcontroller 1500may be supplied with power to operate other functionalities of thehandle assembly 14 in such circumstances, the handle assembly 14 may bein a powered-down state. In a way, the electrical connector 1400 may bein a powered-down state as voltage potentials applied to the electricalcontacts 1401 b-1401 e may not affect the operation of the handleassembly 14. The reader will appreciate that, even though contacts 1401b-1401 e may be in a powered-down state, the electrical contacts 1401 aand 1401 f, which are not in electrical communication with themicrocontroller 1500, may or may not be in a powered-down state. Forinstance, sixth contact 1401 f may remain in electrical communicationwith a ground regardless of whether the handle assembly 14 is in apowered-up or a powered-down state.

Furthermore, the transistor 1408, and/or any other suitable arrangementof transistors, such as transistor 1410, for example, and/or switchesmay be configured to control the supply of power from a power source1404, such as a battery 90 within the handle assembly 14, for example,to the first electrical contact 1401 a regardless of whether the handleassembly 14 is in a powered-up or a powered-down state. In variouscircumstances, the shaft assembly 200, for example, can be configured tochange the state of the transistor 1408 when the shaft assembly 200 isengaged with the handle assembly 14. In certain circumstances, furtherto the below, a magnetic field sensor 1402 can be configured to switchthe state of transistor 1410 which, as a result, can switch the state oftransistor 1408 and ultimately supply power from power source 1404 tofirst contact 1401 a. In this way, both the power circuits and thesignal circuits to the connector 1400 can be powered down when a shaftassembly is not installed to the handle assembly 14 and powered up whena shaft assembly is installed to the handle assembly 14.

In various circumstances, referring again to FIG. 19, the handleassembly 14 can include the magnetic field sensor 1402, for example,which can be configured to detect a detectable element, such as amagnetic element 1407 (FIG. 3), for example, on a shaft assembly, suchas shaft assembly 200, for example, when the shaft assembly is coupledto the handle assembly 14. The magnetic field sensor 1402 can be poweredby a power source 1406, such as a battery, for example, which can, ineffect, amplify the detection signal of the magnetic field sensor 1402and communicate with an input channel of the microcontroller 1500 viathe circuit illustrated in FIG. 19. Once the microcontroller 1500 has areceived an input indicating that a shaft assembly has been at leastpartially coupled to the handle assembly 14, and that, as a result, theelectrical contacts 1401 a-1401 f are no longer exposed, themicrocontroller 1500 can enter into its normal, or powered-up, operatingstate. In such an operating state, the microcontroller 1500 willevaluate the signals transmitted to one or more of the contacts 1401b-1401 e from the shaft assembly and/or transmit signals to the shaftassembly through one or more of the contacts 1401 b-1401 e in normal usethereof. In various circumstances, the shaft assembly 200 may have to befully seated before the magnetic field sensor 1402 can detect themagnetic element 1407. While a magnetic field sensor 1402 can beutilized to detect the presence of the shaft assembly 200, any suitablesystem of sensors and/or switches can be utilized to detect whether ashaft assembly has been assembled to the handle assembly 14, forexample. In this way, further to the above, both the power circuits andthe signal circuits to the connector 1400 can be powered down when ashaft assembly is not installed to the handle assembly 14 and powered upwhen a shaft assembly is installed to the handle assembly 14.

In various examples, as may be used throughout the present disclosure,any suitable magnetic field sensor may be employed to detect whether ashaft assembly has been assembled to the handle assembly 14, forexample. For example, the technologies used for magnetic field sensinginclude Hall effect sensor, search coil, fluxgate, optically pumped,nuclear precession, SQUID, Hall-effect, anisotropic magnetoresistance,giant magnetoresistance, magnetic tunnel junctions, giantmagnetoimpedance, magnetostrictive/piezoelectric composites,magnetodiode, magnetotransistor, fiber optic, magnetooptic, andmicroelectromechanical systems-based magnetic sensors, among others.

Referring to FIG. 19, the microcontroller 1500 may generally comprise amicroprocessor (“processor”) and one or more memory units operationallycoupled to the processor. By executing instruction code stored in thememory, the processor may control various components of the surgicalinstrument, such as the motor, various drive systems, and/or a userdisplay, for example. The microcontroller 1500 may be implemented usingintegrated and/or discrete hardware elements, software elements, and/ora combination of both. Examples of integrated hardware elements mayinclude processors, microprocessors, microcontrollers, integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate arrays (FPGA), logic gates, registers, semiconductor devices,chips, microchips, chip sets, microcontrollers, system-on-chip (SoC),and/or system-in-package (SIP). Examples of discrete hardware elementsmay include circuits and/or circuit elements such as logic gates, fieldeffect transistors, bipolar transistors, resistors, capacitors,inductors, and/or relays. In certain instances, the microcontroller 1500may include a hybrid circuit comprising discrete and integrated circuitelements or components on one or more substrates, for example.

Referring to FIG. 19, the microcontroller 1500 may be an LM 4F230H5QR,available from Texas Instruments, for example. In certain instances, theTexas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Corecomprising on-chip memory of 256 KB single-cycle flash memory, or othernon-volatile memory, up to 40 MHz, a prefetch buffer to improveperformance above 40 MHz, a 32 KB single-cycle serial random accessmemory (SRAM), internal read-only memory (ROM) loaded withStellarisWare® software, 2 KB electrically erasable programmableread-only memory (EEPROM), one or more pulse width modulation (PWM)modules, one or more quadrature encoder inputs (QEI) analog, one or more12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels,among other features that are readily available. Other microcontrollersmay be readily substituted for use with the present disclosure.Accordingly, the present disclosure should not be limited in thiscontext.

As discussed above, the handle assembly 14 and/or the shaft assembly 200can include systems and configurations configured to prevent, or atleast reduce the possibility of, the contacts of the handle electricalconnector 1400 and/or the contacts of the shaft electrical connector1410 from becoming shorted out when the shaft assembly 200 is notassembled, or completely assembled, to the handle assembly 14. Referringto FIG. 3, the handle electrical connector 1400 can be at leastpartially recessed within a cavity 1409 defined in the handle frame 20.The six contacts 1401 a-1401 f of the electrical connector 1400 can becompletely recessed within the cavity 1409. Such arrangements can reducethe possibility of an object accidentally contacting one or more of thecontacts 1401 a-1401 f. Similarly, the shaft electrical connector 1410can be positioned within a recess defined in the shaft chassis 240 whichcan reduce the possibility of an object accidentally contacting one ormore of the contacts 1411 a-1411 f of the shaft electrical connector1410. With regard to the particular example depicted in FIG. 3, theshaft contacts 1411 a-1411 f can comprise male contacts. In at least oneexample, each shaft contact 1411 a-1411 f can comprise a flexibleprojection extending therefrom which can be configured to engage acorresponding handle contact 1401 a-1401 f, for example. The handlecontacts 1401 a-1401 f can comprise female contacts. In at least oneexample, each handle contact 1401 a-1401 f can comprise a flat surface,for example, against which the male shaft contacts 1401 a-1401 f canwipe, or slide, against and maintain an electrically conductiveinterface therebetween. In various instances, the direction in which theshaft assembly 200 is assembled to the handle assembly 14 can beparallel to, or at least substantially parallel to, the handle contacts1401 a-1401 f such that the shaft contacts 1411 a-1411 f slide againstthe handle contacts 1401 a-1401 f when the shaft assembly 200 isassembled to the handle assembly 14. In various alternative examples,the handle contacts 1401 a-1401 f can comprise male contacts and theshaft contacts 1411 a-1411 f can comprise female contacts. In certainalternative examples, the handle contacts 1401 a-1401 f and the shaftcontacts 1411 a-1411 f can comprise any suitable arrangement ofcontacts.

In various instances, the handle assembly 14 can comprise a connectorguard configured to at least partially cover the handle electricalconnector 1400 and/or a connector guard configured to at least partiallycover the shaft electrical connector 1410. A connector guard canprevent, or at least reduce the possibility of, an object accidentallytouching the contacts of an electrical connector when the shaft assemblyis not assembled to, or only partially assembled to, the handle. Aconnector guard can be movable. For instance, the connector guard can bemoved between a guarded position in which it at least partially guards aconnector and an unguarded position in which it does not guard, or atleast guards less of, the connector. In at least one example, aconnector guard can be displaced as the shaft assembly is beingassembled to the handle. For instance, if the handle comprises a handleconnector guard, the shaft assembly can contact and displace the handleconnector guard as the shaft assembly is being assembled to the handle.Similarly, if the shaft assembly comprises a shaft connector guard, thehandle can contact and displace the shaft connector guard as the shaftassembly is being assembled to the handle. In various instances, aconnector guard can comprise a door, for example. In at least oneinstance, the door can comprise a beveled surface which, when contactedby the handle or shaft, can facilitate the displacement of the door in acertain direction. In various instances, the connector guard can betranslated and/or rotated, for example. In certain instances, aconnector guard can comprise at least one film which covers the contactsof an electrical connector. When the shaft assembly is assembled to thehandle, the film can become ruptured. In at least one instance, the malecontacts of a connector can penetrate the film before engaging thecorresponding contacts positioned underneath the film.

As described above, the surgical instrument can include a system whichcan selectively power-up, or activate, the contacts of an electricalconnector, such as the electrical connector 1400, for example. Invarious instances, the contacts can be transitioned between anunactivated condition and an activated condition. In certain instances,the contacts can be transitioned between a monitored condition, adeactivated condition, and an activated condition. For instance, themicrocontroller 1500, for example, can monitor the contacts 1401 a-1401f when a shaft assembly has not been assembled to the handle assembly 14to determine whether one or more of the contacts 1401 a-1401 f may havebeen shorted. The microcontroller 1500 can be configured to apply a lowvoltage potential to each of the contacts 1401 a-1401 f and assesswhether only a minimal resistance is present at each of the contacts.Such an operating state can comprise the monitored condition. In theevent that the resistance detected at a contact is high, or above athreshold resistance, the microcontroller 1500 can deactivate thatcontact, more than one contact, or, alternatively, all of the contacts.Such an operating state can comprise the deactivated condition. If ashaft assembly is assembled to the handle assembly 14 and it is detectedby the microcontroller 1500, as discussed above, the microcontroller1500 can increase the voltage potential to the contacts 1401 a-1401 f.Such an operating state can comprise the activated condition.

The various shaft assemblies disclosed herein may employ sensors andvarious other components that require electrical communication with thecontroller in the housing. These shaft assemblies generally areconfigured to be able to rotate relative to the housing necessitating aconnection that facilitates such electrical communication between two ormore components that may rotate relative to each other. When employingend effectors of the types disclosed herein, the connector arrangementsmust be relatively robust in nature while also being somewhat compact tofit into the shaft assembly connector portion.

Referring to FIG. 20, a non-limiting form of the end effector 300 isillustrated. As described above, the end effector 300 may include theanvil 306 and the staple cartridge 304. In this non-limiting example,the anvil 306 is coupled to an elongate channel 198. For example,apertures 199 can be defined in the elongate channel 198 which canreceive pins 152 extending from the anvil 306 and allow the anvil 306 topivot from an open position to a closed position relative to theelongate channel 198 and staple cartridge 304. In addition, FIG. 20shows a firing bar 172, configured to longitudinally translate into theend effector 300. The firing bar 172 may be constructed from one solidsection, or in various examples, may include a laminate materialcomprising, for example, a stack of steel plates. A distally projectingend of the firing bar 172 can be attached to an E-beam 178 that can,among other things, assist in spacing the anvil 306 from a staplecartridge 304 positioned in the elongate channel 198 when the anvil 306is in a closed position. The E-beam 178 can also include a sharpenedcutting edge 182 which can be used to sever tissue as the E-beam 178 isadvanced distally by the firing bar 172. In operation, the E-beam 178can also actuate, or fire, the staple cartridge 304. The staplecartridge 304 can include a molded cartridge body 194 that holds aplurality of staples 191 resting upon staple drivers 192 withinrespective upwardly open staple cavities 195. A wedge sled 190 is drivendistally by the E-beam 178, sliding upon a cartridge tray 196 that holdstogether the various components of the replaceable staple cartridge 304.The wedge sled 190 upwardly cams the staple drivers 192 to force out thestaples 191 into deforming contact with the anvil 306 while a cuttingsurface 182 of the E-beam 178 severs clamped tissue.

Further to the above, the E-beam 178 can include upper pins 180 whichengage the anvil 306 during firing. The E-beam 178 can further includemiddle pins 184 and a bottom foot 186 which can engage various portionsof the cartridge body 194, cartridge tray 196 and elongate channel 198.When a staple cartridge 304 is positioned within the elongate channel198, a slot 193 defined in the cartridge body 194 can be aligned with aslot 197 defined in the cartridge tray 196 and a slot 189 defined in theelongate channel 198. In use, the E-beam 178 can slide through thealigned slots 193, 197, and 189 wherein, as indicated in FIG. 20, thebottom foot 186 of the E-beam 178 can engage a groove running along thebottom surface of channel 198 along the length of slot 189, the middlepins 184 can engage the top surfaces of cartridge tray 196 along thelength of longitudinal slot 197, and the upper pins 180 can engage theanvil 306. In such circumstances, the E-beam 178 can space, or limit therelative movement between, the anvil 306 and the staple cartridge 304 asthe firing bar 172 is moved distally to fire the staples from the staplecartridge 304 and/or incise the tissue captured between the anvil 306and the staple cartridge 304. Thereafter, the firing bar 172 and theE-beam 178 can be retracted proximally allowing the anvil 306 to beopened to release the two stapled and severed tissue portions (notshown).

Having described a surgical instrument 10 (FIGS. 1-4) in general terms,the description now turns to a detailed description of variouselectrical/electronic components of the surgical instrument 10. Turningnow to FIGS. 21A-21B, where one example of a segmented circuit 2000comprising a plurality of circuit segments 2002 a-2002 g is illustrated.The segmented circuit 2000 comprising the plurality of circuit segments2002 a-2002 g is configured to control a powered surgical instrument,such as, for example, the surgical instrument 10 illustrated in FIGS.1-18A, without limitation. The plurality of circuit segments 2002 a-2002g is configured to control one or more operations of the poweredsurgical instrument 10. A safety processor segment 2002 a (Segment 1)comprises a safety processor 2004. A primary processor segment 2002 b(Segment 2) comprises a primary or main processor 2006. The safetyprocessor 2004 and/or the primary processor 2006 are configured tointeract with one or more additional circuit segments 2002 c-2002 g tocontrol operation of the powered surgical instrument 10. The primaryprocessor 2006 comprises a plurality of inputs coupled to, for example,one or more circuit segments 2002 c-2002 g, a battery 2008, and/or aplurality of switches 2056-2070. The segmented circuit 2000 may beimplemented by any suitable circuit, such as, for example, a printedcircuit board assembly (PCBA) within the powered surgical instrument 10.It should be understood that the term processor as used herein includesany microprocessor, microcontroller, or other basic computing devicethat incorporates the functions of a computer's central processing unit(CPU) on an integrated circuit or at most a few integrated circuits. Theprocessor is a multipurpose, programmable device that accepts digitaldata as input, processes it according to instructions stored in itsmemory, and provides results as output. It is an example of sequentialdigital logic, as it has internal memory. Processors operate on numbersand symbols represented in the binary numeral system.

In one aspect, the main processor 2006 may be any single core ormulticore processor such as those known under the trade name ARM Cortexby Texas Instruments. In one example, the safety processor 2004 may be asafety microcontroller platform comprising two microcontroller-basedfamilies such as TMS570 and RM4x known under the trade name Hercules ARMCortex R4, also by Texas Instruments. Nevertheless, other suitablesubstitutes for microcontrollers and safety processor may be employed,without limitation. In one example, the safety processor 2004 may beconfigured specifically for IEC 61508 and ISO 26262 safety criticalapplications, among others, to provide advanced integrated safetyfeatures while delivering scalable performance, connectivity, and memoryoptions.

In certain instances, the main processor 2006 may be an LM 4F230H5QR,available from Texas Instruments, for example. In at least one example,the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Corecomprising on-chip memory of 256 KB single-cycle flash memory, or othernon-volatile memory, up to 40 MHz, a prefetch buffer to improveperformance above 40 MHz, a 32 KB single-cycle SRAM, internal ROM loadedwith StellarisWare® software, 2 KB EEPROM, one or more PWM modules, oneor more QEI analog, one or more 12-bit ADC with 12 analog inputchannels, among other features that are readily available for theproduct datasheet. Other processors may be readily substituted and,accordingly, the present disclosure should not be limited in thiscontext.

In one aspect, the segmented circuit 2000 comprises an accelerationsegment 2002 c (Segment 3). The acceleration segment 2002 c comprises anacceleration sensor 2022. The acceleration sensor 2022 may comprise, forexample, an accelerometer. The acceleration sensor 2022 is configured todetect movement or acceleration of the powered surgical instrument 10.In some examples, input from the acceleration sensor 2022 is used, forexample, to transition to and from a sleep mode, identify an orientationof the powered surgical instrument, and/or identify when the surgicalinstrument has been dropped. In some examples, the acceleration segment2002 c is coupled to the safety processor 2004 and/or the primaryprocessor 2006.

In some aspects, the segmented circuit 2000 comprises a display segment2002 d (Segment 4). According to various embodiments, the displaysegment 2002 d comprises a display connector (not shown) which iscoupled to the primary processor 2006, one or more display driverintegrated circuits (not shown) which are coupled to the displayconnector, and a display 2028 which is coupled to the one or moredisplay driver integrated circuits. The display connector and the one ormore display driver integrated circuits are shown, for example, in FIG.4B of U.S. patent application Ser. No. 14/226,076, now U.S. Pat. No.9,733,663, the content of which is hereby incorporated by reference inits entirety. The display driver integrated circuits may be integratedwith the display 2028 and/or may be located separately from the display2028. The display 2028 may comprise any suitable display, such as, forexample, an organic light-emitting diode (OLED) display, aliquid-crystal display (LCD), and/or any other suitable display. In someexamples, the display segment 2002 d is coupled to the safety processor2004.

In some aspects, the segmented circuit 2000 comprises a shaft segment2002 e (Segment 5). The shaft segment 2002 e comprises one or morecontrols for a shaft assembly (e.g., shaft assembly 200) coupled to thesurgical instrument 10 and/or one or more controls for an end effector(e.g., end effector 300) coupled to the shaft 200. According to variousembodiments, the shaft segment 2002 e comprises a shaft connector 2030and a shaft printed circuit board assembly (PCBA) 2031. The shaftconnector 2030 is configured to couple the shaft PCBA 2031 to theprimary processor 2006. According to various embodiments, the shaft PCBA2031 comprises a first articulation switch (not shown), a secondarticulation switch (not shown), and a shaft PCBA EEPROM (not shown). Insome examples, the shaft PCBA EEPROM comprises one or more parameters,routines, and/or programs specific to the shaft assembly 200 and/or theshaft PCBA 2031. The shaft PCBA 2031 may be coupled to the shaftassembly 200 and/or integral with the surgical instrument 10. In someexamples, the shaft segment 2002 e comprises a second shaft EEPROM (notshown). The second shaft EEPROM comprises a plurality of algorithms,routines, parameters, and/or other data corresponding to one or moreshaft assemblies 200 and/or end effectors 300 which may be interfacedwith the powered surgical instrument 10. The first articulation switch,the second articulation switch, and the shaft PCBA EEPROMs are shown,for example, in FIG. 4A of U.S. patent application Ser. No. 14/226,076,now U.S. Pat. No. 9,733,663, the content of which is hereby incorporatedby reference in its entirety. According to other embodiments, as shownin FIG. 21A, the shaft segment 2002 e comprises the shaft PCBA 2031, aHall effect sensor 2070 and the shaft connector 2025. The shaft PCBA2031 comprises a low-power microprocessor 2090 with ferroelectric randomaccess memory (FRAM) technology, a mechanical articulation switch 2092,a shaft release Hall effect switch 2094 and flash memory 2034. The Halleffect sensor 2070 is utilized to indicate engagement of the shaftassembly 200 and thus may be considered a shaft engaged switch.

In some aspects, the segmented circuit 2000 comprises a position encodersegment 2002 f (Segment 6). The position encoder segment 2002 fcomprises one or more magnetic rotary position encoders 2040 a-2040 b.The one or more magnetic rotary position encoders 2040 a-2040 b areconfigured to identify the rotational position of a motor 2048, a shaftassembly 200, and/or an end effector 300 of the surgical instrument 10.In some examples, the magnetic rotary position encoders 2040 a-2040 bmay be coupled to the safety processor 2004 and/or the primary processor2006.

In some aspects, the segmented circuit 2000 comprises a motor segment2002 g (Segment 7). The motor segment 2002 g comprises a motor 2048,such as, for example, a brushed DC motor, configured to control one ormore movements of the powered surgical instrument 10. The motor 2048 iscoupled to the primary processor 2006 through a motor controller 2043, aplurality of H-bridge drivers 2042 and a plurality of H-bridgefield-effect transistors (not shown). According to various embodiments,the H-bridge field-effect transistors (FETs) are coupled to the safetyprocessor 2004. The H-bridge FETs are shown, for example, in FIG. 4B ofU.S. patent application Ser. No. 14/226,076, now U.S. Pat. No.9,733,663, the content of which is hereby incorporated by reference inits entirety. The motor controller 2043 controls a first motor flag 2074a and a second motor flag 2074 b to indicate the status and position ofthe motor 2048 to the primary processor 2006. The primary processor 2006provides a pulse-width modulation (PWM) high signal 2076 a, a PWM lowsignal 2076 b, a direction signal 2078, a synchronize signal 2080, and amotor reset signal 2082 to the motor controller 2043 through a buffer2084. A motor current sensor 2046 is coupled in series with the motor2048 to measure the current draw of the motor 2048. The motor currentsensor 2046 is in signal communication with the primary processor 2006and/or the safety processor 2004. In some examples, the motor 2048 iscoupled to a motor electromagnetic interference (EMI) filter (notshown). The EMI filter is shown, for example, in FIG. 3B of U.S. patentapplication Ser. No. 14/226,076, now U.S. Pat. No. 9,733,663, thecontent of which is hereby incorporated by reference in its entirety.

In some aspects, the segmented circuit 2000 comprises a power segment2002 h (Segment 8) configured to provide a segment voltage to each ofthe circuit segments 1102 a-1102 g. A battery 2008 is coupled to thesafety processor 2004, the primary processor 2006, and one or more ofthe additional circuit segments 2002 c-2002 g. The battery 2008 iscoupled to the segmented circuit 2000 by a battery connector 2010 and acurrent sensor 2012. The current sensor 2012 is configured to measurethe total current draw of the segmented circuit 2000. In some examples,one or more voltage converters 2014 a, 2014 b, 2016 are configured toprovide predetermined voltage values to one or more circuit segments2002 a-2002 g. For example, in some examples, the segmented circuit 2000may comprise 3.3V voltage converters 2014 a-2014 b and/or 5V voltageconverters 2016. A boost converter 2018 is configured to provide a boostvoltage up to a predetermined amount, such as, for example, up to 13V.The boost converter 2018 is configured to provide additional voltageand/or current during power intensive operations and prevent brownout orlow-power conditions. A transistor switch (e.g., N-Channel MOSFET) 2015is coupled to the power converters 2014B, 2016.

In some aspects, the safety segment 2002 a comprises a motor powerinterrupt 2020. The motor power interrupt 2020 is coupled between thepower segment 2002 h and the motor segment 2002 g. A transistor switch(e.g., N-Channel MOSFET) 2057 is coupled to the motor power interrupt2020. The safety segment 2002 a is configured to interrupt power to themotor segment 2002 g when an error or fault condition is detected by thesafety processor 2004 and/or the primary processor 2006 as discussed inmore detail herein. Although the circuit segments 2002 a-2002 g areillustrated with all components of the circuit segments 2002 a-2002 hlocated in physical proximity, one skilled in the art will recognizethat a circuit segment 2002 a-2002 h may comprise components physicallyand/or electrically separate from other components of the same circuitsegment 2002 a-2002 g. In some examples, one or more components may beshared between two or more circuit segments 2002 a-2002 g.

In some aspects, a plurality of switches 2056-2070 are coupled to thesafety processor 2004 and/or the primary processor 2006. The pluralityof switches 2056-2070 may be configured to control one or moreoperations of the surgical instrument 10, control one or more operationsof the segmented circuit 2000, and/or indicate a status of the surgicalinstrument 10. For example, a bail-out door switch 2056 is configured toindicate the status of a bail-out door. A plurality of articulationswitches, such as, for example, a left side articulation left switch2058 a, a left side articulation right switch 2060 a, a left sidearticulation center switch 2062 a, a right side articulation left switch2058 b, a right side articulation right switch 2060 b, and a right sidearticulation center switch 2062 b are configured to control articulationof a shaft assembly 200 and/or an end effector 300. A left side reverseswitch 2064 a and a right side reverse switch 2064 b are coupled to theprimary processor 2006. In some examples, the left side switchescomprising the left side articulation left switch 2058 a, the left sidearticulation right switch 2060 a, the left side articulation centerswitch 2062 a, and the left side reverse switch 2064 a are coupled tothe primary processor 2006 by a left flex connector (not shown). Theright side switches comprising the right side articulation left switch2058 b, the right side articulation right switch 2060 b, the right sidearticulation center switch 2062 b, and the right side reverse switch2064 b are coupled to the primary processor 2006 by a right flexconnector (not shown). The left flex connector and the right flexconnector are shown, for example, in FIG. 3A of U.S. patent applicationSer. No. 14/226,076, now U.S. Pat. No. 9,733,663, the content of whichis hereby incorporated by reference in its entirety. In some examples, afiring switch 2066, a clamp release switch 2068, and the Hall effectsensor/shaft engaged switch 2070 are coupled to the primary processor2006.

In some aspects, the plurality of switches 2056-2070 may comprise, forexample, a plurality of handle controls mounted to a handle of thesurgical instrument 10, a plurality of indicator switches, and/or anycombination thereof. In various examples, the plurality of switches2056-2070 allow a surgeon to manipulate the surgical instrument, providefeedback to the segmented circuit 2000 regarding the position and/oroperation of the surgical instrument, and/or indicate unsafe operationof the surgical instrument 10. In some examples, additional or fewerswitches may be coupled to the segmented circuit 2000, one or more ofthe switches 2056-2070 may be combined into a single switch, and/orexpanded to multiple switches. For example, in one example, one or moreof the left side and/or right side articulation switches 2058 a-2064 bmay be combined into a single multi-position switch.

In one aspect, the safety processor 2004 is configured to implement awatchdog function, among other safety operations. The safety processor2004 and the primary processor 2006 of the segmented circuit 2000 are insignal communication. The primary processor 2006 is also coupled to aflash memory 2086. A microprocessor alive heartbeat signal is providedat output 2096. The acceleration segment 2002 c comprises anaccelerometer 2022 configured to monitor movement of the surgicalinstrument 10. In various examples, the accelerometer 2022 may be asingle, double, or triple axis accelerometer. The accelerometer 2022 maybe employed to measure proper acceleration that is not necessarily thecoordinate acceleration (rate of change of velocity). Instead, theaccelerometer sees the acceleration associated with the phenomenon ofweight experienced by a test mass at rest in the frame of reference ofthe accelerometer 2022. For example, the accelerometer 2022 at rest onthe surface of the earth will measure an acceleration g=9.8 m/s²(gravity) straight upwards, due to its weight. Another type ofacceleration that accelerometer 2022 can measure is g-forceacceleration. In various other examples, the accelerometer 2022 maycomprise a single, double, or triple axis accelerometer. Further, theacceleration segment 2002 c may comprise one or more inertial sensors todetect and measure acceleration, tilt, shock, vibration, rotation, andmultiple degrees-of-freedom (DoF). A suitable inertial sensor maycomprise an accelerometer (single, double, or triple axis), amagnetometer to measure a magnetic field in space such as the earth'smagnetic field, and/or a gyroscope to measure angular velocity.

In one aspect, the safety processor 2004 is configured to implement awatchdog function with respect to one or more circuit segments 2002c-2002 h, such as, for example, the motor segment 2002 g. In thisregards, the safety processor 2004 employs the watchdog function todetect and recover from malfunctions of the primary processor 2006.During normal operation, the safety processor 2004 monitors for hardwarefaults or program errors of the primary processor 2006 and to initiatecorrective action or actions. The corrective actions may include placingthe primary processor 2006 in a safe state and restoring normal systemoperation. In one example, the safety processor 2004 is coupled to atleast a first sensor. The first sensor measures a first property of thesurgical instrument 10 (FIGS. 1-4). In some examples, the safetyprocessor 2004 is configured to compare the measured property of thesurgical instrument 10 to a predetermined value. For example, in oneexample, a motor sensor 2040 a (e.g., a magnetic rotary positionencoder) is coupled to the safety processor 2004. The motor sensor 2040a provides motor speed and position information to the safety processor2004. The safety processor 2004 monitors the motor sensor 2040 a andcompares the value to a maximum speed and/or position value and preventsoperation of the motor 2048 above the predetermined values. In someexamples, the predetermined values are calculated based on real-timespeed and/or position of the motor 2048, calculated from values suppliedby a second motor sensor 2040 b (e.g., a magnetic rotary positionencoder) in communication with the primary processor 2006, and/orprovided to the safety processor 2004 from, for example, a memory modulecoupled to the safety processor 2004.

In some aspects, a second sensor is coupled to the primary processor2006. The second sensor is configured to measure the first physicalproperty. The safety processor 2004 and the primary processor 2006 areconfigured to provide a signal indicative of the value of the firstsensor and the second sensor respectively. When either the safetyprocessor 2004 or the primary processor 2006 indicates a value outsideof an acceptable range, the segmented circuit 2000 prevents operation ofat least one of the circuit segments 2002 c-2002 h, such as, forexample, the motor segment 2002 g. For example, in the exampleillustrated in FIGS. 21A-21B, the safety processor 2004 is coupled to afirst motor position sensor 2040 a and the primary processor 2006 iscoupled to a second motor position sensor 2040 b. The motor positionsensors 2040 a, 2040 b may comprise any suitable motor position sensor,such as, for example, a magnetic angle rotary input comprising a sineand cosine output. The motor position sensors 2040 a, 2040 b providerespective signals to the safety processor 2004 and the primaryprocessor 2006 indicative of the position of the motor 2048.

The safety processor 2004 and the primary processor 2006 generate anactivation signal when the values of the first motor sensor 2040 a andthe second motor sensor 2040 b are within a predetermined range. Wheneither the primary processor 2006 or the safety processor 2004 detect avalue outside of the predetermined range, the activation signal isterminated and operation of at least one circuit segment 2002 c-2002 h,such as, for example, the motor segment 2002 g, is interrupted and/orprevented. For example, in some examples, the activation signal from theprimary processor 2006 and the activation signal from the safetyprocessor 2004 are coupled to an AND gate 2059. The AND gate 2059 iscoupled to a motor power switch 2020. The AND gate 2059 maintains themotor power switch 2020 in a closed, or on, position when the activationsignal from both the safety processor 2004 and the primary processor2006 are high, indicating a value of the motor sensors 2040 a, 2040 bwithin the predetermined range. When either of the motor sensors 2040 a,2040 b detect a value outside of the predetermined range, the activationsignal from that motor sensor 2040 a, 2040 b is set low, and the outputof the AND gate 2059 is set low, opening the motor power switch 2020. Insome examples, the value of the first sensor 2040 a and the secondsensor 2040 b is compared, for example, by the safety processor 2004and/or the primary processor 2006. When the values of the first sensorand the second sensor are different, the safety processor 2004 and/orthe primary processor 2006 may prevent operation of the motor segment2002 g.

In some aspects, the safety processor 2004 receives a signal indicativeof the value of the second sensor 2040 b and compares the second sensorvalue to the first sensor value. For example, in one aspect, the safetyprocessor 2004 is coupled directly to a first motor sensor 2040 a. Asecond motor sensor 2040 b is coupled to a primary processor 2006, whichprovides the second motor sensor 2040 b value to the safety processor2004, and/or coupled directly to the safety processor 2004. The safetyprocessor 2004 compares the value of the first motor sensor 2040 to thevalue of the second motor sensor 2040 b. When the safety processor 2004detects a mismatch between the first motor sensor 2040 a and the secondmotor sensor 2040 b, the safety processor 2004 may interrupt operationof the motor segment 2002 g, for example, by cutting power to the motorsegment 2002 g.

In some aspects, the safety processor 2004 and/or the primary processor2006 is coupled to a first sensor 2040 a configured to measure a firstproperty of a surgical instrument and a second sensor 2040 b configuredto measure a second property of the surgical instrument. The firstproperty and the second property comprise a predetermined relationshipwhen the surgical instrument is operating normally. The safety processor2004 monitors the first property and the second property. When a valueof the first property and/or the second property inconsistent with thepredetermined relationship is detected, a fault occurs. When a faultoccurs, the safety processor 2004 takes at least one action, such as,for example, preventing operation of at least one of the circuitsegments, executing a predetermined operation, and/or resetting theprimary processor 2006. For example, the safety processor 2004 may openthe motor power switch 2020 to cut power to the motor circuit segment2002 g when a fault is detected.

In one aspect, the safety processor 2004 is configured to execute anindependent control algorithm. In operation, the safety processor 2004monitors the segmented circuit 2000 and is configured to control and/oroverride signals from other circuit components, such as, for example,the primary processor 2006, independently. The safety processor 2004 mayexecute a preprogrammed algorithm and/or may be updated or programmed onthe fly during operation based on one or more actions and/or positionsof the surgical instrument 10. For example, in one example, the safetyprocessor 2004 is reprogrammed with new parameters and/or safetyalgorithms each time a new shaft and/or end effector is coupled to thesurgical instrument 10. In some examples, one or more safety valuesstored by the safety processor 2004 are duplicated by the primaryprocessor 2006. Two-way error detection is performed to ensure valuesand/or parameters stored by either of the processors 2004, 2006 arecorrect.

In some aspects, the safety processor 2004 and the primary processor2006 implement a redundant safety check. The safety processor 2004 andthe primary processor 2006 provide periodic signals indicating normaloperation. For example, during operation, the safety processor 2004 mayindicate to the primary processor 2006 that the safety processor 2004 isexecuting code and operating normally. The primary processor 2006 may,likewise, indicate to the safety processor 2004 that the primaryprocessor 2006 is executing code and operating normally. In someexamples, communication between the safety processor 2004 and theprimary processor 2006 occurs at a predetermined interval. Thepredetermined interval may be constant or may be variable based on thecircuit state and/or operation of the surgical instrument 10.

FIG. 22 illustrates one example of a power assembly 2100 comprising ausage cycle circuit 2102 configured to monitor a usage cycle count ofthe power assembly 2100. The power assembly 2100 may be coupled to asurgical instrument 2110. The usage cycle circuit 2102 comprises aprocessor 2104 and a use indicator 2106. The use indicator 2106 isconfigured to provide a signal to the processor 2104 to indicate a useof the battery back 2100 and/or a surgical instrument 2110 coupled tothe power assembly 2100. A “use” may comprise any suitable action,condition, and/or parameter such as, for example, changing a modularcomponent of a surgical instrument 2110, deploying or firing adisposable component coupled to the surgical instrument 2110, deliveringelectrosurgical energy from the surgical instrument 2110, reconditioningthe surgical instrument 2110 and/or the power assembly 2100, exchangingthe power assembly 2100, recharging the power assembly 2100, and/orexceeding a safety limitation of the surgical instrument 2110 and/or thebattery back 2100.

In some instances, a usage cycle, or use, is defined by one or morepower assembly 2100 parameters. For example, in one instance, a usagecycle comprises using more than 5% of the total energy available fromthe power assembly 2100 when the power assembly 2100 is at a full chargelevel. In another instance, a usage cycle comprises a continuous energydrain from the power assembly 2100 exceeding a predetermined time limit.For example, a usage cycle may correspond to five minutes of continuousand/or total energy draw from the power assembly 2100. In someinstances, the power assembly 2100 comprises a usage cycle circuit 2102having a continuous power draw to maintain one or more components of theusage cycle circuit 2102, such as, for example, the use indicator 2106and/or a counter 2108, in an active state.

The processor 2104 maintains a usage cycle count. The usage cycle countindicates the number of uses detected by the use indicator 2106 for thepower assembly 2100 and/or the surgical instrument 2110. The processor2104 may increment and/or decrement the usage cycle count based on inputfrom the use indicator 2106. The usage cycle count is used to controlone or more operations of the power assembly 2100 and/or the surgicalinstrument 2110. For example, in some instances, a power assembly 2100is disabled when the usage cycle count exceeds a predetermined usagelimit. Although the instances discussed herein are discussed withrespect to incrementing the usage cycle count above a predeterminedusage limit, those skilled in the art will recognize that the usagecycle count may start at a predetermined amount and may be decrementedby the processor 2104. In this instance, the processor 2104 initiatesand/or prevents one or more operations of the power assembly 2100 whenthe usage cycle count falls below a predetermined usage limit.

The usage cycle count is maintained by a counter 2108. The counter 2108comprises any suitable circuit, such as, for example, a memory module,an analog counter, and/or any circuit configured to maintain a usagecycle count. In some instances, the counter 2108 is formed integrallywith the processor 2104. In other instances, the counter 2108 comprisesa separate component, such as, for example, a solid state memory module.In some instances, the usage cycle count is provided to a remote system,such as, for example, a central database. The usage cycle count istransmitted by a communications module 2112 to the remote system. Thecommunications module 2112 is configured to use any suitablecommunications medium, such as, for example, wired and/or wirelesscommunication. In some instances, the communications module 2112 isconfigured to receive one or more instructions from the remote system,such as, for example, a control signal when the usage cycle countexceeds the predetermined usage limit.

In some instances, the use indicator 2106 is configured to monitor thenumber of modular components used with a surgical instrument 2110coupled to the power assembly 2100. A modular component may comprise,for example, a modular shaft, a modular end effector, and/or any othermodular component. In some instances, the use indicator 2106 monitorsthe use of one or more disposable components, such as, for example,insertion and/or deployment of a staple cartridge within an end effectorcoupled to the surgical instrument 2110. The use indicator 2106comprises one or more sensors for detecting the exchange of one or moremodular and/or disposable components of the surgical instrument 2110.

In some instances, the use indicator 2106 is configured to monitorsingle patient surgical procedures performed while the power assembly2100 is installed. For example, the use indicator 2106 may be configuredto monitor firings of the surgical instrument 2110 while the powerassembly 2100 is coupled to the surgical instrument 2110. A firing maycorrespond to deployment of a staple cartridge, application ofelectrosurgical energy, and/or any other suitable surgical event. Theuse indicator 2106 may comprise one or more circuits for measuring thenumber of firings while the power assembly 2100 is installed. The useindicator 2106 provides a signal to the processor 2104 when a singlepatient procedure is performed and the processor 2104 increments theusage cycle count.

In some instances, the use indicator 2106 comprises a circuit configuredto monitor one or more parameters of the power source 2114, such as, forexample, a current draw from the power source 2114. The one or moreparameters of the power source 2114 correspond to one or more operationsperformable by the surgical instrument 2110, such as, for example, acutting and sealing operation. The use indicator 2106 provides the oneor more parameters to the processor 2104, which increments the usagecycle count when the one or more parameters indicate that a procedurehas been performed.

In some instances, the use indicator 2106 comprises a timing circuitconfigured to increment a usage cycle count after a predetermined timeperiod. The predetermined time period corresponds to a single patientprocedure time, which is the time required for an operator to perform aprocedure, such as, for example, a cutting and sealing procedure. Whenthe power assembly 2100 is coupled to the surgical instrument 2110, theprocessor 2104 polls the use indicator 2106 to determine when the singlepatient procedure time has expired. When the predetermined time periodhas elapsed, the processor 2104 increments the usage cycle count. Afterincrementing the usage cycle count, the processor 2104 resets the timingcircuit of the use indicator 2106.

In some instances, the use indicator 2106 comprises a time constant thatapproximates the single patient procedure time. In one example, theusage cycle circuit 2102 comprises a resistor-capacitor (RC) timingcircuit 2506. The RC timing circuit comprises a time constant defined bya resistor-capacitor pair. The time constant is defined by the values ofthe resistor and the capacitor. In one example, the usage cycle circuit2552 comprises a rechargeable battery and a clock. When the powerassembly 2100 is installed in a surgical instrument, the rechargeablebattery is charged by the power source. The rechargeable batterycomprises enough power to run the clock for at least the single patientprocedure time. The clock may comprise a real time clock, a processorconfigured to implement a time function, or any other suitable timingcircuit.

Referring still to FIG. 22, in some instances, the use indicator 2106comprises a sensor configured to monitor one or more environmentalconditions experienced by the power assembly 2100. For example, the useindicator 2106 may comprise an accelerometer. The accelerometer isconfigured to monitor acceleration of the power assembly 2100. The powerassembly 2100 comprises a maximum acceleration tolerance. Accelerationabove a predetermined threshold indicates, for example, that the powerassembly 2100 has been dropped. When the use indicator 2106 detectsacceleration above the maximum acceleration tolerance, the processor2104 increments a usage cycle count. In some instances, the useindicator 2106 comprises a moisture sensor. The moisture sensor isconfigured to indicate when the power assembly 2100 has been exposed tomoisture. The moisture sensor may comprise, for example, an immersionsensor configured to indicate when the power assembly 2100 has beenfully immersed in a cleaning fluid, a moisture sensor configured toindicate when moisture is in contact with the power assembly 2100 duringuse, and/or any other suitable moisture sensor.

In some instances, the use indicator 2106 comprises a chemical exposuresensor. The chemical exposure sensor is configured to indicate when thepower assembly 2100 has come into contact with harmful and/or dangerouschemicals. For example, during a sterilization procedure, aninappropriate chemical may be used that leads to degradation of thepower assembly 2100. The processor 2104 increments the usage cycle countwhen the use indicator 2106 detects an inappropriate chemical.

In some instances, the usage cycle circuit 2102 is configured to monitorthe number of reconditioning cycles experienced by the power assembly2100. A reconditioning cycle may comprise, for example, a cleaningcycle, a sterilization cycle, a charging cycle, routine and/orpreventative maintenance, and/or any other suitable reconditioningcycle. The use indicator 2106 is configured to detect a reconditioningcycle. For example, the use indicator 2106 may comprise a moisturesensor to detect a cleaning and/or sterilization cycle. In someinstances, the usage cycle circuit 2102 monitors the number ofreconditioning cycles experienced by the power assembly 2100 anddisables the power assembly 2100 after the number of reconditioningcycles exceeds a predetermined threshold.

The usage cycle circuit 2102 may be configured to monitor the number ofpower assembly 2100 exchanges. The usage cycle circuit 2102 incrementsthe usage cycle count each time the power assembly 2100 is exchanged.When the maximum number of exchanges is exceeded the usage cycle circuit2102 locks out the power assembly 2100 and/or the surgical instrument2110. In some instances, when the power assembly 2100 is coupled thesurgical instrument 2110, the usage cycle circuit 2102 identifies theserial number of the power assembly 2100 and locks the power assembly2100 such that the power assembly 2100 is usable only with the surgicalinstrument 2110. In some instances, the usage cycle circuit 2102increments the usage cycle each time the power assembly 2100 is removedfrom and/or coupled to the surgical instrument 2110.

In some instances, the usage cycle count corresponds to sterilization ofthe power assembly 2100. The use indicator 2106 comprises a sensorconfigured to detect one or more parameters of a sterilization cycle,such as, for example, a temperature parameter, a chemical parameter, amoisture parameter, and/or any other suitable parameter. The processor2104 increments the usage cycle count when a sterilization parameter isdetected. The usage cycle circuit 2102 disables the power assembly 2100after a predetermined number of sterilizations. In some instances, theusage cycle circuit 2102 is reset during a sterilization cycle, avoltage sensor to detect a recharge cycle, and/or any suitable sensor.The processor 2104 increments the usage cycle count when areconditioning cycle is detected. The usage cycle circuit 2102 isdisabled when a sterilization cycle is detected. The usage cycle circuit2102 is reactivated and/or reset when the power assembly 2100 is coupledto the surgical instrument 2110. In some instances, the use indicatorcomprises a zero power indicator. The zero power indicator changes stateduring a sterilization cycle and is checked by the processor 2104 whenthe power assembly 2100 is coupled to a surgical instrument 2110. Whenthe zero power indicator indicates that a sterilization cycle hasoccurred, the processor 2104 increments the usage cycle count.

A counter 2108 maintains the usage cycle count. In some instances, thecounter 2108 comprises a non-volatile memory module. The processor 2104increments the usage cycle count stored in the non-volatile memorymodule each time a usage cycle is detected. The memory module may beaccessed by the processor 2104 and/or a control circuit, such as, forexample, the control circuit 2000. When the usage cycle count exceeds apredetermined threshold, the processor 2104 disables the power assembly2100. In some instances, the usage cycle count is maintained by aplurality of circuit components. For example, in one instance, thecounter 2108 comprises a resistor (or fuse) pack. After each use of thepower assembly 2100, a resistor (or fuse) is burned to an open position,changing the resistance of the resistor pack. The power assembly 2100and/or the surgical instrument 2110 reads the remaining resistance. Whenthe last resistor of the resistor pack is burned out, the resistor packhas a predetermined resistance, such as, for example, an infiniteresistance corresponding to an open circuit, which indicates that thepower assembly 2100 has reached its usage limit. In some instances, theresistance of the resistor pack is used to derive the number of usesremaining.

In some instances, the usage cycle circuit 2102 prevents further use ofthe power assembly 2100 and/or the surgical instrument 2110 when theusage cycle count exceeds a predetermined usage limit. In one instance,the usage cycle count associated with the power assembly 2100 isprovided to an operator, for example, utilizing a screen formedintegrally with the surgical instrument 2110. The surgical instrument2110 provides an indication to the operator that the usage cycle counthas exceeded a predetermined limit for the power assembly 2100, andprevents further operation of the surgical instrument 2110.

In some instances, the usage cycle circuit 2102 is configured tophysically prevent operation when the predetermined usage limit isreached. For example, the power assembly 2100 may comprise a shieldconfigured to deploy over contacts of the power assembly 2100 when theusage cycle count exceeds the predetermined usage limit. The shieldprevents recharge and use of the power assembly 2100 by covering theelectrical connections of the power assembly 2100.

In some instances, the usage cycle circuit 2102 is located at leastpartially within the surgical instrument 2110 and is configured tomaintain a usage cycle count for the surgical instrument 2110. FIG. 22illustrates one or more components of the usage cycle circuit 2102within the surgical instrument 2110 in phantom, illustrating thealternative positioning of the usage cycle circuit 2102. When apredetermined usage limit of the surgical instrument 2110 is exceeded,the usage cycle circuit 2102 disables and/or prevents operation of thesurgical instrument 2110. The usage cycle count is incremented by theusage cycle circuit 2102 when the use indicator 2106 detects a specificevent and/or requirement, such as, for example, firing of the surgicalinstrument 2110, a predetermined time period corresponding to a singlepatient procedure time, based on one or more motor parameters of thesurgical instrument 2110, in response to a system diagnostic indicatingthat one or more predetermined thresholds are met, and/or any othersuitable requirement. As discussed above, in some instances, the useindicator 2106 comprises a timing circuit corresponding to a singlepatient procedure time. In other instances, the use indicator 2106comprises one or more sensors configured to detect a specific eventand/or condition of the surgical instrument 2110.

In some instances, the usage cycle circuit 2102 is configured to preventoperation of the surgical instrument 2110 after the predetermined usagelimit is reached. In some instances, the surgical instrument 2110comprises a visible indicator to indicate when the predetermined usagelimit has been reached and/or exceeded. For example, a flag, such as ared flag, may pop-up from the surgical instrument 2110, such as from thehandle, to provide a visual indication to the operator that the surgicalinstrument 2110 has exceeded the predetermined usage limit. As anotherexample, the usage cycle circuit 2102 may be coupled to a display formedintegrally with the surgical instrument 2110. The usage cycle circuit2102 displays a message indicating that the predetermined usage limithas been exceeded. The surgical instrument 2110 may provide an audibleindication to the operator that the predetermined usage limit has beenexceeded. For example, in one instance, the surgical instrument 2110emits an audible tone when the predetermined usage limit is exceeded andthe power assembly 2100 is removed from the surgical instrument 2110.The audible tone indicates the last use of the surgical instrument 2110and indicates that the surgical instrument 2110 should be disposed orreconditioned.

In some instances, the usage cycle circuit 2102 is configured totransmit the usage cycle count of the surgical instrument 2110 to aremote location, such as, for example, a central database. The usagecycle circuit 2102 comprises a communications module 2112 configured totransmit the usage cycle count to the remote location. Thecommunications module 2112 may utilize any suitable communicationssystem, such as, for example, wired or wireless communications system.The remote location may comprise a central database configured tomaintain usage information. In some instances, when the power assembly2100 is coupled to the surgical instrument 2110, the power assembly 2100records a serial number of the surgical instrument 2110. The serialnumber is transmitted to the central database, for example, when thepower assembly 2100 is coupled to a charger. In some instances, thecentral database maintains a count corresponding to each use of thesurgical instrument 2110. For example, a bar code associated with thesurgical instrument 2110 may be scanned each time the surgicalinstrument 2110 is used. When the use count exceeds a predeterminedusage limit, the central database provides a signal to the surgicalinstrument 2110 indicating that the surgical instrument 2110 should bediscarded.

The surgical instrument 2110 may be configured to lock and/or preventoperation of the surgical instrument 2110 when the usage cycle countexceeds a predetermined usage limit. In some instances, the surgicalinstrument 2110 comprises a disposable instrument and is discarded afterthe usage cycle count exceeds the predetermined usage limit. In otherinstances, the surgical instrument 2110 comprises a reusable surgicalinstrument which may be reconditioned after the usage cycle countexceeds the predetermined usage limit. The surgical instrument 2110initiates a reversible lockout after the predetermined usage limit ismet. A technician reconditions the surgical instrument 2110 and releasesthe lockout, for example, utilizing a specialized technician keyconfigured to reset the usage cycle circuit 2102.

In some aspects, the segmented circuit 2000 is configured for sequentialstart-up. An error check is performed by each circuit segment 2002a-2002 g prior to energizing the next sequential circuit segment 2002a-2002 g. FIG. 23 illustrates one example of a process for sequentiallyenergizing a segmented circuit 2270, such as, for example, the segmentedcircuit 2000. When a battery 2008 is coupled to the segmented circuit2000, the safety processor 2004 is energized 2272. The safety processor2004 performs a self-error check 2274. When an error is detected 2276 a,the safety processor stops energizing the segmented circuit 2000 andgenerates an error code 2278 a. When no errors are detected 2276 b, thesafety processor 2004 initiates 2278 b power-up of the primary processor2006. The primary processor 2006 performs a self-error check. When noerrors are detected, the primary processor 2006 begins sequentialpower-up of each of the remaining circuit segments 2278 b. Each circuitsegment is energized and error checked by the primary processor 2006.When no errors are detected, the next circuit segment is energized 2278b. When an error is detected, the safety processor 2004 and/or theprimary process stops energizing the current segment and generates anerror 2278 a. The sequential start-up continues until all of the circuitsegments 2002 a-2002 g have been energized.

FIG. 24 illustrates one aspect of a power segment 2302 comprising aplurality of daisy chained power converters 2314, 2316, 2318. The powersegment 2302 comprises a battery 2308. The battery 2308 is configured toprovide a source voltage, such as, for example, 12V. A current sensor2312 is coupled to the battery 2308 to monitor the current draw of asegmented circuit and/or one or more circuit segments. The currentsensor 2312 is coupled to an FET switch 2313. The battery 2308 iscoupled to one or more voltage converters 2309, 2314, 2316. An always onconverter 2309 provides a constant voltage to one or more circuitcomponents, such as, for example, a motion sensor 2322. The always onconverter 2309 comprises, for example, a 3.3V converter. The always onconverter 2309 may provide a constant voltage to additional circuitcomponents, such as, for example, a safety processor (not shown). Thebattery 2308 is coupled to a boost converter 2318. The boost converter2318 is configured to provide a boosted voltage above the voltageprovided by the battery 2308. For example, in the illustrated example,the battery 2308 provides a voltage of 12V. The boost converter 2318 isconfigured to boost the voltage to 13V. The boost converter 2318 isconfigured to maintain a minimum voltage during operation of a surgicalinstrument, for example, the surgical instrument 10 (FIGS. 1-4).Operation of a motor can result in the power provided to the primaryprocessor 2306 dropping below a minimum threshold and creating abrownout or reset condition in the primary processor 2306. The boostconverter 2318 ensures that sufficient power is available to the primaryprocessor 2306 and/or other circuit components, such as the motorcontroller 2343, during operation of the surgical instrument 10. In someexamples, the boost converter 2318 is coupled directly one or morecircuit components, such as, for example, an OLED display 2388.

The boost converter 2318 is coupled to one or more step-down convertersto provide voltages below the boosted voltage level. A first voltageconverter 2316 is coupled to the boost converter 2318 and provides afirst stepped-down voltage to one or more circuit components. In theillustrated example, the first voltage converter 2316 provides a voltageof 5V. The first voltage converter 2316 is coupled to a rotary positionencoder 2340. A FET switch 2317 is coupled between the first voltageconverter 2316 and the rotary position encoder 2340. The FET switch 2317is controlled by the processor 2306. The processor 2306 opens the FETswitch 2317 to deactivate the position encoder 2340, for example, duringpower intensive operations. The first voltage converter 2316 is coupledto a second voltage converter 2314 configured to provide a secondstepped-down voltage. The second stepped-down voltage comprises, forexample, 3.3V. The second voltage converter 2314 is coupled to aprocessor 2306. In some examples, the boost converter 2318, the firstvoltage converter 2316, and the second voltage converter 2314 arecoupled in a daisy chain configuration. The daisy chain configurationallows the use of smaller, more efficient converters for generatingvoltage levels below the boosted voltage level. The examples, however,are not limited to the particular voltage range(s) described in thecontext of this specification.

FIG. 25 illustrates one aspect of a segmented circuit 2400 configured tomaximize power available for critical and/or power intense functions.The segmented circuit 2400 comprises a battery 2408. The battery 2408 isconfigured to provide a source voltage such as, for example, 12V. Thesource voltage is provided to a plurality of voltage converters 2409,2418. An always-on voltage converter 2409 provides a constant voltage toone or more circuit components, for example, a motion sensor 2422 and asafety processor 2404. The always-on voltage converter 2409 is directlycoupled to the battery 2408. The always-on converter 2409 provides avoltage of 3.3V, for example. The examples, however, are not limited tothe particular voltage range(s) described in the context of thisspecification.

The segmented circuit 2400 comprises a boost converter 2418. The boostconverter 2418 provides a boosted voltage above the source voltageprovided by the battery 2408, such as, for example, 13V. The boostconverter 2418 provides a boosted voltage directly to one or morecircuit components, such as, for example, an OLED display 2488 and amotor controller 2443. By coupling the OLED display 2488 directly to theboost converter 2418, the segmented circuit 2400 eliminates the need fora power converter dedicated to the OLED display 2488. The boostconverter 2418 provides a boosted voltage to the motor controller 2443and the motor 2448 during one or more power intensive operations of themotor 2448, such as, for example, a cutting operation. The boostconverter 2418 is coupled to a step-down converter 2416. The step-downconverter 2416 is configured to provide a voltage below the boostedvoltage to one or more circuit components, such as, for example, 5V. Thestep-down converter 2416 is coupled to, for example, a FET switch 2451and a position encoder 2440. The FET switch 2451 is coupled to theprimary processor 2406. The primary processor 2406 opens the FET switch2451 when transitioning the segmented circuit 2400 to sleep mode and/orduring power intensive functions requiring additional voltage deliveredto the motor 2448. Opening the FET switch 2451 deactivates the positionencoder 2440 and eliminates the power draw of the position encoder 2440.The examples, however, are not limited to the particular voltagerange(s) described in the context of this specification.

The step-down converter 2416 is coupled to a linear converter 2414. Thelinear converter 2414 is configured to provide a voltage of, forexample, 3.3V. The linear converter 2414 is coupled to the primaryprocessor 2406. The linear converter 2414 provides an operating voltageto the primary processor 2406. The linear converter 2414 may be coupledto one or more additional circuit components. The examples, however, arenot limited to the particular voltage range(s) described in the contextof this specification.

The segmented circuit 2400 comprises a bailout switch 2456. The bailoutswitch 2456 is coupled to a bailout door on the surgical instrument 10.The bailout switch 2456 and the safety processor 2404 are coupled to anAND gate 2419. The AND gate 2419 provides an input to a FET switch 2413.When the bailout switch 2456 detects a bailout condition, the bailoutswitch 2456 provides a bailout shutdown signal to the AND gate 2419.When the safety processor 2404 detects an unsafe condition, such as, forexample, due to a sensor mismatch, the safety processor 2404 provides ashutdown signal to the AND gate 2419. In some examples, both the bailoutshutdown signal and the shutdown signal are high during normal operationand are low when a bailout condition or an unsafe condition is detected.When the output of the AND gate 2419 is low, the FET switch 2413 isopened and operation of the motor 2448 is prevented. In some examples,the safety processor 2404 utilizes the shutdown signal to transition themotor 2448 to an off state in sleep mode. A third input to the FETswitch 2413 is provided by a current sensor 2412 coupled to the battery2408. The current sensor 2412 monitors the current drawn by the circuit2400 and opens the FET switch 2413 to shut-off power to the motor 2448when an electrical current above a predetermined threshold is detected.The FET switch 2413 and the motor controller 2443 are coupled to a bankof FET switches 2445 configured to control operation of the motor 2448.

A motor current sensor 2446 is coupled in series with the motor 2448 toprovide a motor current sensor reading to a current monitor 2447. Thecurrent monitor 2447 is coupled to the primary processor 2406. Thecurrent monitor 2447 provides a signal indicative of the current draw ofthe motor 2448. The primary processor 2406 may utilize the signal fromthe motor current 2447 to control operation of the motor, for example,to ensure the current draw of the motor 2448 is within an acceptablerange, to compare the current draw of the motor 2448 to one or moreother parameters of the circuit 2400 such as, for example, the positionencoder 2440, and/or to determine one or more parameters of a treatmentsite. In some examples, the current monitor 2447 may be coupled to thesafety processor 2404.

In some aspects, actuation of one or more handle controls, such as, forexample, a firing trigger, causes the primary processor 2406 to decreasepower to one or more components while the handle control is actuated.For example, in one example, a firing trigger controls a firing strokeof a cutting member. The cutting member is driven by the motor 2448.Actuation of the firing trigger results in forward operation of themotor 2448 and advancement of the cutting member. During firing, theprimary processor 2406 opens the FET switch 2451 to remove power fromthe position encoder 2440. The deactivation of one or more circuitcomponents allows higher power to be delivered to the motor 2448. Whenthe firing trigger is released, full power is restored to thedeactivated components, for example, by closing the FET switch 2451 andreactivating the position encoder 2440.

In some aspects, the safety processor 2404 controls operation of thesegmented circuit 2400. For example, the safety processor 2404 mayinitiate a sequential power-up of the segmented circuit 2400, transitionof the segmented circuit 2400 to and from sleep mode, and/or mayoverride one or more control signals from the primary processor 2406.For example, in the illustrated example, the safety processor 2404 iscoupled to the step-down converter 2416. The safety processor 2404controls operation of the segmented circuit 2400 by activating ordeactivating the step-down converter 2416 to provide power to theremainder of the segmented circuit 2400.

FIG. 26 illustrates one aspect of a power system 2500 comprising aplurality of daisy chained power converters 2514, 2516, 2518 configuredto be sequentially energized. The plurality of daisy chained powerconverters 2514, 2516, 2518 may be sequentially activated by, forexample, a safety processor during initial power-up and/or transitionfrom sleep mode. The safety processor may be powered by an independentpower converter (not shown). For example, in one example, when a batteryvoltage VBATT is coupled to the power system 2500 and/or anaccelerometer detects movement in sleep mode, the safety processorinitiates a sequential start-up of the daisy chained power converters2514, 2516, 2518. The safety processor activates the 13V boost section2518. The boost section 2518 is energized and performs a self-check. Insome examples, the boost section 2518 comprises an integrated circuit2520 configured to boost the source voltage and to perform a self check.A diode D prevents power-up of a 5V supply section 2516 until the boostsection 2518 has completed a self-check and provided a signal to thediode D indicating that the boost section 2518 did not identify anyerrors. In some examples, this signal is provided by the safetyprocessor. The examples, however, are not limited to the particularvoltage range(s) described in the context of this specification.

The 5V supply section 2516 is sequentially powered-up after the boostsection 2518. The 5V supply section 2516 performs a self-check duringpower-up to identify any errors in the 5V supply section 2516. The 5Vsupply section 2516 comprises an integrated circuit 2515 configured toprovide a step-down voltage from the boost voltage and to perform anerror check. When no errors are detected, the 5V supply section 2516completes sequential power-up and provides an activation signal to the3.3V supply section 2514. In some examples, the safety processorprovides an activation signal to the 3.3V supply section 2514. The 3.3Vsupply section comprises an integrated circuit 2513 configured toprovide a step-down voltage from the 5V supply section 2516 and performa self-error check during power-up. When no errors are detected duringthe self-check, the 3.3V supply section 2514 provides power to theprimary processor. The primary processor is configured to sequentiallyenergize each of the remaining circuit segments. By sequentiallyenergizing the power system 2500 and/or the remainder of a segmentedcircuit, the power system 2500 reduces error risks, allows forstabilization of voltage levels before loads are applied, and preventslarge current draws from all hardware being turned on simultaneously inan uncontrolled manner. The examples, however, are not limited to theparticular voltage range(s) described in the context of thisspecification.

In one aspect, the power system 2500 comprises an over voltageidentification and mitigation circuit. The over voltage identificationand mitigation circuit is configured to detect a monopolar returncurrent in the surgical instrument and interrupt power from the powersegment when the monopolar return current is detected. The over voltageidentification and mitigation circuit is configured to identify groundfloatation of the power system. The over voltage identification andmitigation circuit comprises a metal oxide varistor. The over voltageidentification and mitigation circuit comprises at least one transientvoltage suppression diode.

FIG. 27 illustrates one aspect of a segmented circuit 2600 comprising anisolated control section 2602. The isolated control section 2602isolates control hardware of the segmented circuit 2600 from a powersection (not shown) of the segmented circuit 2600. The control section2602 comprises, for example, a primary processor 2606, a safetyprocessor (not shown), and/or additional control hardware, for example,a FET Switch 2617. The power section comprises, for example, a motor, amotor driver, and/or a plurality of motor MOSFETS. The isolated controlsection 2602 comprises a charging circuit 2603 and a rechargeablebattery 2608 coupled to a 5V power converter 2616. The charging circuit2603 and the rechargeable battery 2608 isolate the primary processor2606 from the power section. In some examples, the rechargeable battery2608 is coupled to a safety processor and any additional supporthardware. Isolating the control section 2602 from the power sectionallows the control section 2602, for example, the primary processor2606, to remain active even when main power is removed, provides afilter, through the rechargeable battery 2608, to keep noise out of thecontrol section 2602, isolates the control section 2602 from heavyswings in the battery voltage to ensure proper operation even duringheavy motor loads, and/or allows for real-time operating system (RTOS)to be used by the segmented circuit 2600. In some examples, therechargeable battery 2608 provides a stepped-down voltage to the primaryprocessor, such as, for example, 3.3V. The examples, however, are notlimited to the particular voltage range(s) described in the context ofthis specification.

FIGS. 28A and 28B illustrate another aspect of a control circuit 3000configured to control the powered surgical instrument 10, illustrated inFIGS. 1-18A. As shown in FIGS. 18A, 28B, the handle assembly 14 mayinclude a motor 3014 which can be controlled by a motor driver 3015 andcan be employed by the firing system of the surgical instrument 10. Invarious forms, the motor 3014 may be a DC brushed driving motor having amaximum rotation of, approximately, 25,000 RPM, for example. In otherarrangements, the motor 3014 may include a brushless motor, a cordlessmotor, a synchronous motor, a stepper motor, or any other suitableelectric motor. In certain circumstances, the motor driver 3015 maycomprise an H-Bridge FETs 3019, as illustrated in FIG. 28B, for example.The motor 3014 can be powered by a power assembly 3006, which can bereleasably mounted to the handle assembly 14. The power assembly 3006 isconfigured to supply control power to the surgical instrument 10. Thepower assembly 3006 may comprise a battery which may include a number ofbattery cells connected in series that can be used as the power sourceto power the surgical instrument 10. In such configuration, the powerassembly 3006 may be referred to as a battery pack. In certaincircumstances, the battery cells of the power assembly 3006 may bereplaceable and/or rechargeable. In at least one example, the batterycells can be Lithium-Ion batteries which can be separably couplable tothe power assembly 3006.

Examples of drive systems and closure systems that are suitable for usewith the surgical instrument 10 are disclosed in U.S. Provisional PatentApplication Ser. No. 61/782,866, entitled CONTROL SYSTEM OF A SURGICALINSTRUMENT, and filed Mar. 14, 2013, the entire disclosure of which isincorporated by reference herein in its entirety. For example, theelectric motor 3014 can include a rotatable shaft (not shown) that mayoperably interface with a gear reducer assembly that can be mounted inmeshing engagement with a set, or rack, of drive teeth on alongitudinally-movable drive member. In use, a voltage polarity providedby the battery can operate the electric motor 3014 to drive thelongitudinally-movable drive member to effectuate the end effector 300.For example, the motor 3014 can be configured to drive thelongitudinally-movable drive member to advance a firing mechanism tofire staples into tissue captured by the end effector 300 from a staplecartridge assembled with the end effector 300 and/or advance a cuttingmember to cut tissue captured by the end effector 300, for example.

As illustrated in FIGS. 28A and 28B and as described below in greaterdetail, the power assembly 3006 may include a power managementcontroller 3016 which can be configured to modulate the power output ofthe power assembly 3006 to deliver a first power output to power themotor 3014 to advance the cutting member while the interchangeable shaftassembly 200 is coupled to the handle assembly 14 and to deliver asecond power output to power the motor 3014 to advance the cuttingmember while the interchangeable shaft assembly 200 is coupled to thehandle assembly 14, for example. Such modulation can be beneficial inavoiding transmission of excessive power to the motor 3014 beyond therequirements of an interchangeable shaft assembly that is coupled to thehandle assembly 14.

The shaft assembly 200 may include the shaft PCBA 3031 which includesthe shaft assembly controller 3022 which can communicate with the powermanagement controller 3016 through an interface (e.g., interface 3024 ofFIG. 29) while the shaft assembly 200 and the power assembly 3006 arecoupled to the handle assembly 14. For example, the interface maycomprise a first interface portion 3025 which may include one or moreelectric connectors for coupling engagement with corresponding shaftassembly electric connectors and a second interface portion 3027 whichmay include one or more electric connectors for coupling engagement withcorresponding power assembly electric connectors to permit electricalcommunication between the shaft assembly controller 3022 and the powermanagement controller 3016 while the shaft assembly 200 and the powerassembly 3006 are coupled to the handle assembly 14. One or morecommunication signals can be transmitted through the interface tocommunicate one or more of the power requirements of the attachedinterchangeable shaft assembly 200 to the power management controller3016. In response, the power management controller 3016 may modulate thepower output of the battery of the power assembly 3006, as describedbelow in greater detail, in accordance with the power requirements ofthe attached shaft assembly 200. In certain circumstances, one or moreof the electric connectors may comprise switches which can be activatedafter mechanical coupling engagement of the handle assembly 14 to theshaft assembly 200 and/or to the power assembly 3006 to allow electricalcommunication between the shaft assembly controller 3022 and the powermanagement controller 3016.

In certain circumstances, the interface can facilitate transmission ofthe one or more communication signals between the power managementcontroller 3016 and the shaft assembly controller 3022 by routing suchcommunication signals through a main controller 3017 residing in thehandle assembly 14, for example. In other circumstances, the interfacecan facilitate a direct line of communication between the powermanagement controller 3016 and the shaft assembly controller 3022through the handle assembly 14 while the shaft assembly 200 and thepower assembly 3006 are coupled to the handle assembly 14.

In one instance, the main microcontroller 3017 may be any single core ormulticore processor such as those known under the trade name ARM Cortexby Texas Instruments. In one instance, the surgical instrument 10 (FIGS.1-4) may comprise a power management controller 3016 such as, forexample, a safety microcontroller platform comprising twomicrocontroller-based families such as TMS570 and RM4x known under thetrade name Hercules ARM Cortex R4, also by Texas Instruments.Nevertheless, other suitable substitutes for microcontrollers and safetyprocessor may be employed, without limitation. In one instance, thesafety processor 2004 (FIG. 21A) may be configured specifically for IEC61508 and ISO 26262 safety critical applications, among others, toprovide advanced integrated safety features while delivering scalableperformance, connectivity, and memory options.

In certain instances, the microcontroller 3017 may be an LM 4F230H5QR,available from Texas Instruments, for example. In at least one example,the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Corecomprising on-chip memory of 256 KB single-cycle flash memory, or othernon-volatile memory, up to 40 MHz, a prefetch buffer to improveperformance above 40 MHz, a 32 KB single-cycle serial random accessmemory (SRAM), internal read-only memory (ROM) loaded withStellarisWare® software, 2 KB electrically erasable programmableread-only memory (EEPROM), one or more pulse width modulation (PWM)modules, one or more quadrature encoder inputs (QEI) analog, one or more12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels,among other features that are readily available for the productdatasheet. The present disclosure should not be limited in this context.

The power assembly 3006 may include a power management circuit which maycomprise the power management controller 3016, a power modulator 3038,and a current sense circuit 3036. The power management circuit can beconfigured to modulate power output of the battery based on the powerrequirements of the shaft assembly 200 while the shaft assembly 200 andthe power assembly 3006 are coupled to the handle assembly 14. Forexample, the power management controller 3016 can be programmed tocontrol the power modulator 3038 of the power output of the powerassembly 3006 and the current sense circuit 3036 can be employed tomonitor power output of the power assembly 3006 to provide feedback tothe power management controller 3016 about the power output of thebattery so that the power management controller 3016 may adjust thepower output of the power assembly 3006 to maintain a desired output.

It is noteworthy that the power management controller 3016 and/or theshaft assembly controller 3022 each may comprise one or more processorsand/or memory units which may store a number of software modules.Although certain modules and/or blocks of the surgical instrument 10 maybe described by way of example, it can be appreciated that a greater orlesser number of modules and/or blocks may be used. Further, althoughvarious instances may be described in terms of modules and/or blocks tofacilitate description, such modules and/or blocks may be implemented byone or more hardware components, e.g., processors, Digital SignalProcessors (DSPs), Programmable Logic Devices (PLDs), ApplicationSpecific Integrated Circuits (ASICs), circuits, registers and/orsoftware components, e.g., programs, subroutines, logic and/orcombinations of hardware and software components.

In certain instances, the surgical instrument 10 may comprise an outputdevice 3042 which may include one or more devices for providing asensory feedback to a user. Such devices may comprise, for example,visual feedback devices (e.g., an LCD display screen, LED indicators),audio feedback devices (e.g., a speaker, a buzzer) or tactile feedbackdevices (e.g., haptic actuators). In certain circumstances, the outputdevice 3042 may comprise a display 3043 which may be included in thehandle assembly 14. The shaft assembly controller 3022 and/or the powermanagement controller 3016 can provide feedback to a user of thesurgical instrument 10 through the output device 3042. The interface(e.g. interface 3024 of FIG. 29) can be configured to connect the shaftassembly controller 3022 and/or the power management controller 3016 tothe output device 3042. The reader will appreciate that the outputdevice 3042 can instead be integrated with the power assembly 3006. Insuch circumstances, communication between the output device 3042 and theshaft assembly controller 3022 may be accomplished through the interfacewhile the shaft assembly 200 is coupled to the handle assembly 14.

FIG. 29 is a block diagram the surgical instrument of FIG. 1illustrating interfaces (collectively 3024) between the handle assembly14 and the power assembly 3006 and between the handle assembly 14 andthe interchangeable shaft assembly 200. As shown in FIG. 29, the powerassembly 3006 may include a power management circuit 3034 which maycomprise the power management controller 3016, a power modulator 3038, acurrent sense circuit 3036 and a power assembly connector 3032. Thepower management circuit 3034 can be configured to modulate power outputof the battery 3007 based on the power requirements of the shaftassembly 200 while the shaft assembly 200 and the power assembly 3006are coupled to the handle assembly 14. For example, the power managementcontroller 3016 can be programmed to control the power modulator 3038 ofthe power output of the power assembly 3006 and the current sensecircuit 3036 can be employed to monitor power output of the powerassembly 3006 to provide feedback to the power management controller3016 about the power output of the battery 3007 so that the powermanagement controller 3016 may adjust the power output of the powerassembly 3006 to maintain a desired output. The power assembly connector3032 is configured to connect to the power assembly connector 3030 ofthe handle assembly 14 at the interface 3027 to connect the powerassembly 3006 to the handle assembly 14.

The shaft assembly 200 includes the shaft assembly controller 3022 and ashaft assembly connector 3028. The shaft assembly connector 3028 isconfigured to connect to the shaft assembly connector 3026 of the handleassembly 14 at the interface 3025 to connect the shaft assembly 200 tothe handle assembly 14. As shown in FIG. 29, the handle assembly 14 mayinclude the main microcontroller 3017 and the output device 3042 whichcomprises the display 3043.

As described hereinabove, various components may cooperate to assist inthe control of a motor of a powered surgical instrument. For example,for the powered surgical instrument 10, the motor current sensor 2046measures the current being delivered to the motor 2048 and delivers aninput signal representative of the measured current to the mainprocessor 2006, which in turn applies pulse width modulation signals tothe motor controller 2043, which in turn provides control signals to thegate terminals of the FETS 2044 to control the amount of currentdelivered to the motor 2048 over time from the battery 2008, as well asthe direction of rotation of the motor 2048. One motor current sensor2046 may be utilized to measure the current being delivered to the motor2048 when the motor is rotating in a first direction and another motorcurrent sensor 2046 may be utilized to measure the current beingdelivered to the motor 2048 when the motor is rotating in a seconddirection. Collectively, such components may be considered to form aportion of a control circuit/system or a motor control circuit/system.In various embodiments, in order to measure the current being deliveredto the motor 2048, the motor current sensor 2046 is positioned tomeasure the current flowing in the H-bridge circuit (the H-bridgecircuit includes the FETS 2044 and allows a voltage to be applied acrossthe motor 2048 in either direction to allow the motor 2048 to rotate ina first direction and a second direction) between the motor 2048 and aFET 2044 which is upstream to the motor 2048. The measured current canbe utilized to control the motor 2048, and by extension, to control aforce applied to the firing drive system 80 of the powered surgicalinstrument 10.

In practice, it is relatively difficult to position a motor currentsensor 2046 to measure the current flowing in the H-bridge circuitbetween the motor 2048 and a FET 2044 which is upstream to the motor2048. Therefore, according to various embodiments, it is desired toutilize a current other than the current measured in the H-bridgecircuit to control the motor 2048. For example, in lieu of utilizing thecurrent measured in the H-bridge circuit as described hereinabove, anout-of-phase current downstream of the H-bridge can be utilized tocontrol the motor 2048.

FIG. 30 illustrates a simplified representation of various embodimentsof a surgical stapler 3100. According to various embodiments, thesurgical stapler 3100 includes a drive system, an electric motor 3102, abattery 3104, and a control system. The drive system, which is not shownin FIG. 30 for purposes of simplicity, may be similar or identical tothe firing drive system 80. The electric motor 3102 is mechanicallycoupled to the drive system, and may be similar or identical to themotor 2048. The battery 3104 is electrically couplable to the electricmotor 3102, and may be similar or identical to the battery 2008. Thecontrol system is electrically connected to the electric motor 3102, andincludes an H-bridge circuit, a first inductive element 3120, a secondinductive element 3122, a first resistive element 3124, a secondresistive element 3126, a first sensor 3128 and a second sensor 3130.The H-bridge circuit which includes a first switching device 3110, asecond switching device 3112, a third switching device 3114 and a fourthswitching device 3116. The first, second, third and fourth switchingdevices 3110-3116 may be any suitable type of switching devices, and maybe similar or identical to the FETS 2044. The H-bridge circuit alsodefines a high side and a low side relative to the electric motor 3102.The high side includes first and second legs, with the first switchingdevice 3110 being part of the first leg and the second switching device3112 being part of the second leg. The low side includes third andfourth legs, with the third switching device 3114 being part of thethird leg and the fourth switching device 3116 being part of the fourthleg. The high side of the H-bridge circuit is considered the upstreamside of the H-bridge circuit and the low side of the H-bridge circuit isconsidered the downstream side of the H-bridge circuit. The electricmotor 3102 is electrically couplable to the battery 3104 via theH-bridge circuit.

The first inductive element 3120 is electrically connected in serieswith the fourth switching device 3116, downstream of the fourthswitching device 3116. The first inductive element 3120 may be embodiedas any suitable type of inductive element. For example, according tovarious embodiments, the first inductive element 3120 may be embodied asan inductor. Although the first inductive element 3120 is shown as asingle inductor, it will be appreciated that the first inductive element3120 may include any number of inductive elements. The second inductiveelement 3122 is electrically connected in series with the thirdswitching device 3114, downstream of the third switching device 3114.The second inductive element 3122 may be embodied as any suitable typeof inductive element. For example, according to various embodiments, thesecond inductive element 3122 may be embodied as an inductor. Althoughthe second inductive element 3122 is shown as a single inductor, it willbe appreciated that the second inductive element 3122 may include anynumber of inductive elements. The first and second inductive elements3120, 3122 may be the same or different, and may embodied as anysuitable type of inductive element. For example, the first and secondinductive elements 3120, 3122 may be embodied as inductors and theinductors may have the same or different henry values.

The first resistive element 3124 is electrically connected in serieswith the first inductive element 3120. The first resistive element 3124may be embodied as any suitable type of resistive element. For example,according to various embodiments, the first resistive element 3124 maybe embodied as a resistor. Although the first resistive element 3124 isshown as a single resistor, it will be appreciated that the firstresistive element 3124 may include any number of resistive elements. Thesecond resistive element 3126 is electrically connected in series withthe second inductive element 3122. The second resistive element 3126 maybe embodied as any suitable type of resistive element. For example,according to various embodiments, the second resistive element 3126 maybe embodied as a resistor. Although the second resistive element 3126 isshown as a single resistor, it will be appreciated that the secondresistive element 3126 may include any number of resistive elements. Thefirst and second resistive elements 3124, 3126 may be the same ordifferent, and may embodied as any suitable type of resistive element.For example, as shown in according to various embodiments, the first andsecond resistive elements 3124, 3126 may be embodied as resistors, andthe resistors may have the same or different ohm values.

The first sensor 3128 may be positioned proximate the first resistiveelement 3124 and is configured to sense/measure a current entering,passing through, exiting from or downstream of the first resistiveelement 3124. The first sensor 3124 may be any suitable type of sensorconfigured to sense/measure a current. The second sensor 3130 may bepositioned proximate the second resistive element 3126 and is configuredto sense/measure a current entering, passing through, exiting from ordownstream of the second resistive element 3126. The second sensor 3126may be any suitable type of sensor configured to sense/measure acurrent.

In operation, when the first and fourth switching devices 3110, 3116 are“closed” and the second and third switching devices 3112, 3114 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a first direction (e.g., a direction which causes acomponent of the drive system to advance distally). For this condition,the path of the current is from the positive terminal of the battery3104, through the first switching device 3110, through the electricmotor 3102, through the fourth switching device 3116, through the firstinductive element 3120, through the first resistive element 3124 andback to the negative terminal of the battery 3104. Initially, thecurrent through the first inductive element 3120 is zero, then itincreases over time until it is equal to the battery voltage divided bythe series resistance between the battery 3104 and the first inductiveelement 3120. In other words, the first inductive element 3120 initiallyresists any change in the current flowing through the first inductiveelement 3120. Due to the variation in the amount of current flowingthrough the first inductive element 3120 over time, the current flowingthrough the first resistive element 3124 will also vary over time,initially starting at zero then increasing over time until it is equalto the battery voltage divided by the series resistance between thebattery 3104 and the first resistive element 3124. The current flowingthrough the first resistive element 3124 may be sensed/measured by thefirst sensor 3128. Responsive to the sensed current, the first sensor3128 may output a signal which is indicative of the magnitude of thesensed current. The output signal from the first sensor 3128 may beinput to the main processor 2006 to control the electric motor 3102, andby extension, to control a force applied to the drive system of thesurgical stapler 3100 when the electric motor 3102 is operating in thefirst direction.

Similarly, when the second and third switching devices 3112, 3114 are“closed” and the first and fourth switching devices 3110, 3116 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a second direction (e.g., a direction which causes acomponent of the drive system to retract proximally). For thiscondition, the path of the current is from the positive terminal of thebattery 3104, through the second switching device 3112, through theelectric motor 3102, through the third switching device 3114, throughthe second inductive element 3122, through the second resistive element3126 and back to the negative terminal of the battery 3104. Initially,the current through the second inductive element 3122 is zero, then itincreases over time until it is equal to the battery voltage divided bythe series resistance between the battery 3104 and the second inductiveelement 3122. In other words, the second inductive element 3122initially resists any change in the current flowing through the secondinductive element 3122. Due to the variation in the amount of currentflowing through the second inductive element 3122 over time, the currentflowing through the second resistive element 3126 will also vary overtime, initially starting at zero then increasing over time until it isequal to the battery voltage divided by the series resistance betweenthe battery 3104 and the second resistive element 3126. The currentflowing through the second resistive element 3126 may be sensed/measuredby the second sensor 3130. Responsive to the sensed current, the secondsensor 3130 may output a signal which is indicative of the magnitude ofthe sensed current. The output signal from the second sensor 3130 may beinput to the main processor 2006 to control the electric motor 3102, andby extension, to control a force applied to the drive system of thesurgical stapler 3100 when the electric motor 3102 is operating in thesecond direction.

Although the surgical stapler 3100 is only shown in FIG. 30 as having aninductive element and a resistive element downstream of each lower legof the H-bridge circuit, it will be appreciated that according to otherembodiments, the surgical stapler 3100 may include a single inductiveelement/resistive element pair electrically connected downstream ofeither the third leg or the fourth leg of the H-bridge circuit.Additionally, according to other embodiments, othercombinations/arrangements of electrical components may be electricallyconnected downstream of the lower legs of the H-bridge circuit.

FIG. 31 illustrates a simplified representation of various embodimentsof a surgical stapler 3200. The surgical stapler 3200 is similar to thesurgical stapler 3100, but is different in that the surgical stapler3200 includes a different combination and arrangement of electricalcomponents downstream of the lower legs of the H-bridge circuit. Thesurgical stapler 3200 includes first and second inductive elements 3220,3222, first and second resistive elements 3224, 3226, first and secondsensors 3228, 3230 and first and second capacitive elements 3232, 3234.The first and second inductive elements 3220, 3222 may be similar oridentical to the first and second inductive elements 3120, 3122. Thefirst and second resistive elements 3224, 3226 may be similar oridentical to first and second resistive elements 3124, 3126. The firstand second sensors 3228, 3230 may be similar or identical to the firstand second sensors 3128, 3130. For example, according to variousembodiments, the first and second sensors 3228, 3230 may be configuredto sense/measure a current. According to other embodiments, the firstand second sensors 3228, 3230 may be configured to sense a voltage.According to yet other embodiments, the first and second sensors 3228,3230 may be configured to sense a current and/or a voltage.

The first capacitive element 3232 is electrically connected in serieswith the first inductive element 3220 and in parallel with the firstresistive element 3224. The first capacitive element 3232 may beembodied as any suitable type of capacitive element. For example,according to various embodiments, the first capacitive element 3232 maybe embodied as a capacitor. Although the first capacitive element 3232is shown as a single capacitor, it will be appreciated that the firstcapacitive element 3232 may include any number of capacitive elements.The second capacitive element 3234 is electrically connected in serieswith the second inductive element 3222 and in parallel with the secondresistive element 3226. The second capacitive element 3234 may beembodied as any suitable type of capacitive element. For example,according to various embodiments, the second capacitive element 3234 maybe embodied as a capacitor. Although the second capacitive element 3234is shown as a single capacitor, it will be appreciated that the secondcapacitive element 3234 may include any number of capacitive elements.The first and second capacitive elements 3232, 3234 may be the same ordifferent, and may embodied as any suitable type of capacitive element.For example, according to various embodiments, the first and secondcapacitive elements 3232, 3234 may be embodied as capacitors, and thecapacitors may have the same or different farad values.

In operation, when the first and fourth switching devices 3110, 3116 are“closed” and the second and third switching devices 3112, 3114 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a first direction (e.g., a direction which causes acomponent of the drive system to advance distally). For this condition,the path of the current is from the positive terminal of the battery3104, through the first switching device 3110, through the electricmotor 3102, through the fourth switching device 3116, through both thefirst resistive element 3224 and the first inductive element 3220/firstcapacitance element 3232 pair, and back to the negative terminal of thebattery 3104. Initially, the current through the first inductive element3220 is zero, then it increases over time until it is equal to thebattery voltage divided by the series resistance between the battery3104 and the first inductive element 3220. Due to the variation in theamount of current flowing through the first inductive element 3220 overtime, the current flowing through the first capacitive element 3232 willalso vary over time, initially starting at zero then increasing overtime until it is equal to the battery voltage divided by the seriesresistance between the battery 3104 and the first capacitive element3232. The current downstream of the first capacitance element 3232 (ordownstream of the first resistive element 3224) may be sensed/measuredby the first sensor 3228. Responsive to the sensed current, the firstsensor 3228 may output a signal which is indicative of the magnitude ofthe sensed current. The output signal from the first sensor 3228 may beinput to the main processor 2006 to control the electric motor 3102, andby extension, to control a force applied to the drive system of thesurgical stapler 3100 when the electric motor 3102 is operating in thefirst direction.

With respect to voltage, initially the voltage across the firstcapacitive element 3232 is zero, then it increases over time until it isequal to the battery voltage less any voltage drops between the battery3104 and the first capacitive element 3232. In other words, the firstcapacitive element 3232 initially resists any change in the voltageacross it. Thus, there is a variation in the amount of voltage acrossthe first capacitive element 3232 over time, initially starting at zerothen increasing over time until it is equal to the battery voltage lessany voltage drops between the battery 3104 and the first capacitiveelement 3232. By measuring a voltage across the first capacitive element3232 while the electric motor 3102 is operating in the first direction,the measured voltage will have a magnitude which is different than amagnitude of a voltage measured at the electric motor 3102. The voltageacross the first capacitive element 3232 may be sensed/measured by thefirst sensor 3228. Responsive to the sensed voltage, the first sensor3228 may output a signal which is indicative of the magnitude of thesensed voltage. The output signal from the first sensor 3228 may beinput to the main processor 2006 to control the electric motor 3102, andby extension, to control a force applied to the drive system of thesurgical stapler 3100 when the electric motor 3102 is operating in thefirst direction.

Similarly, when the second and third switching devices 3112, 3114 are“closed” and the first and fourth switching devices 3110, 3116 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a second direction (e.g., a direction which causes acomponent of the drive system to retract proximally). For thiscondition, the path of the current is from the positive terminal of thebattery 3104, through the second switching device 3112, through theelectric motor 3102, through the third switching device 3114, throughboth the second resistive element 3226 and the second inductive element3222/second capacitance element 3234 pair, and back to the negativeterminal of the battery 3104. Initially, the current through the secondinductive element 3222 is zero, then it increases over time until it isequal to the battery voltage divided by the series resistance betweenthe battery 3104 and the second inductive element 3222. Due to thevariation in the amount of current flowing through the second inductiveelement 3222 over time, the current flowing through the secondcapacitive element 3234 will also vary over time, initially starting atzero then increasing over time until it is equal to the battery voltagedivided by the series resistance between the battery 3104 and the secondcapacitive element 3234. The current downstream of the secondcapacitance element 3234 (or downstream of the second resistive element3226) may be sensed/measured by the second sensor 3230. Responsive tothe sensed current, the second sensor 3230 may output a signal which isindicative of the magnitude of the sensed current. The output signalfrom the second sensor 3230 may be input to the main processor 2006 tocontrol the electric motor 3102, and by extension, to control a forceapplied to the drive system of the surgical stapler 3100 when theelectric motor 3102 is operating in the second direction.

With respect to voltage, initially the voltage across the secondcapacitive element 3234 is zero, then it increases over time until it isequal to the battery voltage less any voltage drops between the battery3104 and the second capacitive element 3234. In other words, the secondcapacitive element 3234 initially resists any change in the voltageacross it. Thus, there is a variation in the amount of voltage acrossthe second capacitive element 3234 over time, initially starting at zerothen increasing over time until it is equal to the battery voltage lessany voltage drops between the battery 3104 and the second capacitiveelement 3234. By measuring a voltage across the second capacitiveelement 3234 while the electric motor 3102 is operating in the seconddirection, the measured voltage will have a magnitude which is differentthan a magnitude of a voltage measured at the electric motor 3102. Thevoltage across the second capacitive element 3234 may be sensed/measuredby the second sensor 3230. Responsive to the sensed voltage, the secondsensor 3230 may output a signal which is indicative of the magnitude ofthe sensed voltage. The output signal from the second sensor 3230 may beinput to the main processor 2006 to control the electric motor 3102, andby extension, to control a force applied to the drive system of thesurgical stapler 3100 when the electric motor 3102 is operating in thesecond direction.

Although the surgical stapler 3200 is only shown in FIG. 31 as having anresistive element and an inductive element/capacitive element pairdownstream of each lower leg of the H-bridge circuit, it will beappreciated that according to other embodiments, the surgical stapler3200 may include a single resistive element and a single inductiveelement/capacitive element pair electrically connected downstream ofeither the third leg or the fourth leg of the H-bridge circuit.

FIG. 32 illustrates a simplified representation of a surgical stapler3300 according to various embodiments. The surgical stapler 3300 issimilar to the surgical stapler 3200, but is different in that thesurgical stapler 3200 includes a different combination and arrangementof electrical components downstream of the lower legs of the H-bridgecircuit. The surgical stapler 3300 includes first and second inductiveelements 3320, 3322, third and fourth inductive elements 3336, 3338,first and second resistive elements 3324, 3326, first and second sensors3328, 3330 and first and second capacitive elements 3332, 3334. Thefirst and second inductive elements 3320, 3322 may be similar oridentical to the first and second inductive elements 3120, 3122. Thefirst and second resistive elements 3324, 3326 may be similar oridentical to first and second resistive elements 3124, 3126. The firstand second sensors 3328, 3330 may be similar or identical to the firstand second sensors 3228, 3230. The first and second capacitive elements3332, 3334 may be similar or identical to first and second capacitiveelements 3232, 3234.

The first inductive element 3320 is electrically connected in serieswith the fourth switching device 3116 and is magnetically coupled withthe second inductive element 3336. The first and second inductiveelements 3320, 3336 may be embodied as coupled inductors or maycollectively form a portion of a transformer. The first and secondinductive elements 3320, 3336 may be the same or different, and mayembodied as any suitable type of inductive element. For example,according to various embodiments, the first and second inductiveelements 3320, 3336 may be embodied as inductors, and the inductors mayhave the same or different henry values. Although the first inductiveelement 3320 is shown as a single inductor and the second inductiveelement 3336 is shown as a single inductor, it will be appreciated thatthe first inductive element 3320 and/or the second inductive element3336 may each include any number of inductive elements. Similarly, thethird inductive element 3322 is electrically connected in series withthe third switching device 3114 and is magnetically coupled with thefourth inductive element 3338. The third and fourth inductive elements3332, 3338 may be embodied as coupled inductors or may collectively forma portion of a transformer. The third and fourth inductive elements3332, 3338 may be the same or different, and may embodied as anysuitable type of inductive element. For example, according to variousembodiments, the third and fourth inductive elements 3332, 3338 may beembodied as inductors, and the inductors may have the same or differenthenry values. Although the third inductive element 3322 is shown as asingle inductor and the fourth inductive element 3338 is shown as asingle inductor, it will be appreciated that the third inductive element3322 and/or the fourth inductive element 3338 may each include anynumber of inductive elements.

The first resistive element 3324 is electrically connected in serieswith the second inductive element 3336. The second resistive element3326 is electrically connected in series with the fourth inductiveelement 3338. The first capacitive element 3332 is electricallyconnected in series with the first resistive element 3324. The secondcapacitive element 3334 is electrically connected in series with thesecond resistive element 3326. Collectively, the second inductiveelement 3336, the first resistive element 3324 and the first capacitiveelement 3332 form a LRC circuit (e.g., a filter) which is magneticallycoupled to the first inductive element 3320. The LRC circuit isconfigured to filter away certain components (e.g., switching currents,harmonics, etc.) of the current exiting the fourth switching device3116. Similarly, the fourth inductive element 3338, the second resistiveelement 3326 and the second capacitive element 3334 form a second LRCcircuit (e.g., a filter) which is magnetically coupled to the secondinductive element 3322. The second LRC circuit is configured to filteraway certain components (e.g., switching currents, harmonics, etc.) ofthe current exiting the third switching device 3114. Although the twofilters are shown as LRC circuits, it will be appreciated that accordingto various embodiments, the three components of each filter may bearranged in a different order (e.g., a RLC circuit), and one filter maybe arranged differently than the other filter.

In operation, when the first and fourth switching devices 3110, 3116 are“closed” and the second and third switching devices 3112, 3114 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a first direction (e.g., a direction which causes acomponent of the drive system to advance distally). For this condition,the path of the current is from the positive terminal of the battery3104, through the first switching device 3110, through the electricmotor 3102, through the fourth switching device 3116, through firstinductive element 3320 and back to the negative terminal of the battery3104. Initially, the current through the first inductive element 3320 iszero, then it increases over time until it is equal to the batteryvoltage divided by the series resistance between the battery 3104 andthe first inductive element 3320. The varying current passing throughthe first inductive element 3320 induces a varying electromotive force(EMF) or voltage across the third inductive element 3336. The voltageinduces a current in the LRC circuit. The current in the LRC circuit isa “filtered” current in comparison to the current exiting the fourthswitching device 3116 and has a magnitude which is different than themagnitude of the current exiting the fourth switching device 3116. TheLRC current may be sensed/measured by the first sensing device 3328.Responsive to the sensed LRC current, the first sensor 3328 may output asignal which is indicative of the magnitude of the sensed current. Theoutput signal from the first sensor 3328 may be input to the mainprocessor 2006 to control the electric motor 3102, and by extension, tocontrol a force applied to the drive system of the surgical stapler 3100when the electric motor 3102 is operating in the first direction.Additionally, the voltage across the first capacitive element 3332 willbe different than the voltage at the electric motor 3102. The firstsensor 3328 may be configured to sense/measure the voltage across thefirst capacitive element 3332. Responsive to the sensed voltage, thefirst sensor 3328 may output a signal which is indicative of themagnitude of the sensed voltage. The output signal from the first sensor3328 may be input to the main processor 2006 to control the electricmotor 3102, and by extension, to control a force applied to the drivesystem of the surgical stapler 3100 when the electric motor 3102 isoperating in the first direction.

Similarly, when the second and third switching devices 3112, 3114 are“closed” and the first and fourth switching devices 3110, 3116 are“open”, the electric motor 3102 is able to draw current from the battery3104 and rotate in a second direction (e.g., a direction which causes acomponent of the drive system to retract proximally). For thiscondition, the path of the current is from the positive terminal of thebattery 3104, through the second switching device 3112, through theelectric motor 3102, through the third switching device 3114, throughsecond inductive element 3322 and back to the negative terminal of thebattery 3104. Initially, the current through the second inductiveelement 3322 is zero, then it increases over time until it is equal tothe battery voltage divided by the series resistance between the battery3104 and the second inductive element 3322. The varying current passingthrough the second inductive element 3332 induces a varyingelectromotive force (EMF) or voltage across the fourth inductive element3338. The voltage induces a current in the second LRC circuit. Thecurrent in the second LRC circuit is a “filtered” current in comparisonto the current exiting the third switching device 3114 and has amagnitude which is different than the magnitude of the current exitingthe third switching device 3114. The LRC current may be sensed/measuredby the second sensing device 3330. Responsive to the sensed LRC current,the second sensor 3330 may output a signal which is indicative of themagnitude of the sensed current. The output signal from the secondsensor 3330 may be input to the main processor 2006 to control theelectric motor 3102, and by extension, to control a force applied to thedrive system of the surgical stapler 3100 when the electric motor 3102is operating in the second direction. Additionally, the voltage acrossthe second capacitive element 3334 will be different than the voltage atthe electric motor 3102. The second sensor 3330 may be configured tosense/measure the voltage across the second capacitive element 3334.Responsive to the sensed voltage, the second sensor 3330 may output asignal which is indicative of the magnitude of the sensed voltage. Theoutput signal from the second sensor 3330 may be input to the mainprocessor 2006 to control the electric motor 3102, and by extension, tocontrol a force applied to the drive system of the surgical stapler 3100when the electric motor 3102 is operating in the second direction.

Although the surgical stapler 330 is shown in FIG. 32 as having two LRCcircuits, each coupled to inductive elements which are downstream ofdifferent legs on the downstream side of the H-bridge circuit, it willbe appreciated that according to other embodiments, the surgical stapler3300 may include a single LRC circuit coupled to a single inductiveelement which is downstream of either the third leg or the fourth leg ofthe H-bridge circuit.

For each of the surgical staplers/instruments described hereinabove,both battery current and recirculation current flows in the H-bridgecircuit. An example of battery current and recirculation currentwaveforms are shown in FIG. 33. In general, when a pulse widthmodulation circuit of the surgical stapler (e.g., a pulse widthmodulation circuit of the main processor 2006) provides a high signal(e.g., a voltage signal which is above a baseline value) to the motorcontroller 2043, the motor controller 2043 controls the switchingdevices in the H-bridge circuit such that a voltage is applied from thebattery 3104 to the electric motor 3102. The electric motor 3102 drawsan increasing amount of current from the battery 3104, eventuallycausing the electric motor 3102 to rotate. The increasing batterycurrent is shown as the “A” portions of FIG. 33. When the pulse widthmodulation circuit of the surgical stapler transitions from providing ahigh signal to providing a low signal (e.g., a voltage signal which isnot above a baseline value) to the motor controller 2043, the motorcontroller 2043 controls the switching devices in the H-bridge circuitvoltage such that no voltage is applied to the electric motor 3102 fromthe battery 3104. When the voltage applied by the battery 3104 isinterrupted, the electric motor 3102 does not draw any current from thebattery 3104. However, because the electric motor 3102 was rotating, theelectric motor 3102 acts like a generator while the electric motor 3102is still rotating. While the electric motor 3102 is acting like agenerator, the electric motor 3102 produces a recirculation currentwhich gradually diminishes to zero. The diminishing recirculationcurrent is shown as the “B” portions of FIG. 33. The shape of therecirculation curve can vary based on the inductance of the electricmotor 3102 and the resistance of the recirculation loop.

Therefore, in order to measure the total average current in theH-bridge, both battery current and recirculation current are measured.Although the battery current can be sensed relatively easily by acurrent sensor (e.g., current sensor 2012) positioned proximate thebattery 3104, the current sensor positioned proximate the battery 3104will not sense the recirculating current. Although a current sensorpositioned to sense a current in the H-bridge proximate the electricmotor 3102 would sense the recirculation current, as indicatedhereinabove it is relatively difficult to position a current sensor inthe H-bridge circuit.

According to various embodiments, each of the above-described surgicalstaplers may be configured to utilize predicted recirculation currentvalues to determine an average total current associated with theelectric motor 3102, and the average total current may be utilized tocontrol the electric motor 3102, and by extension, to control a forceapplied to the drive system of the surgical stapler when the motor isoperating in the first or second direction. For such embodiments, thecontrol system includes a battery current sensor positioned to sense thebattery current, and the control system is configured to predictrecirculating current values based on the sensed battery current.

The recirculation current may be predicted from the measured batterycurrent in any suitable manner. For example, according to variousembodiments, the recirculation current may be predicted based on acharacterization of the battery current. For example, the recirculationcurrent may be predicted in the following manner. First, the batterycurrent sensor of the control system takes a plurality of batterycurrent measurements while a pulse signal generated by the pulse widthmodulation circuit is “high” (above a baseline value). Such samples areindicated by the dots shown on the “A” portions of FIG. 33. Second, thecontrol system (e.g., the main processor 2006) fits the battery currentmeasurements to a first curve representative of the following equation:

I=(V _(B) /R)(1−e ^(−tR/L))

where V_(B) is the battery voltage, R is the resistance, t is the timeand L is the inductance. The values for the resistance R and theinductance L are known and stored in the handle assembly 14. The aboveequation is representative of a charging current curve for an inductor(e.g., the motor). At t=0, the current I=0. As t approaches infinity,the current I=V_(B)/R. Third, given the measured battery current I, thecontrol system (e.g., the main processor 2006) determines the value ofV_(B). Fourth, the control system (e.g., the main processor 2006)utilizes the value of V_(B) as determined above in the followingequation to predict values of the recirculating current at various timeswhile the pulse signal is not high:

I=(V _(B) /R)(e ^(−tR/L))

where R is the resistance, t is the time and L is the inductance. Thevalues for the resistance R and the inductance L are known and stored inthe handle assembly 14. The above equation is representative of thedischarge current curve for an inductor (e.g., the motor). At t=0, thecurrent I=V_(B)/R. As t approaches infinity, the current I=0.

Once the recirculating current values are predicted as described above,the control system (e.g., the main processor 2006) fits therecirculating current values to a second curve representative of thefollowing equation:

I=(V _(B) /R)(e ^(−tR/L))

where R is the resistance, t is the time and L is the inductance. Thevalues for the resistance R and the inductance L are known and stored inthe handle assembly 14. Next, the control system (e.g., the mainprocessor 2006) determines the intersection of the first and secondcurves. The intersection is representative of an inflection point of acurve which includes a battery current component and a recirculatingcurve component. From this point, the control system (e.g., the mainprocessor 2006) determines the area under the first curve up to theintersection and the area under the second curve after the intersection.Next, the control system (e.g., the main processor 2006) adds the areasunder the first and second curves to determine the average total currentat the motor 3102. Finally, the determined average total current at themotor 3102 may be input to or utilized by the main processor 2006 tocontrol the electric motor 3102, and by extension, to control a forceapplied to the drive system of the surgical stapler when the motor isoperating in the first or second direction.

According to other embodiments, the recirculation current may bepredicted based on a characterization of the peaks of the measuredbattery current. For example, the recirculation current may be predictedin the following manner. First, the battery current sensor of thecontrol system takes a plurality of battery current measurements overmultiple periods of the PWM duty cycle. An example of such sampling isshown in FIG. 34, where the dots represent the sampled battery current.During recirculation, the battery current is zero. Second, the controlsystem (e.g., the main processor 2006) pulls out the maximum value ofthe samples (in FIG. 34, the sample “M” has the highest value),designates the maximum value as the ending condition of a batterycurrent curve representative of the following equation:

I=(V _(B) /R)(1−e ^(−tR/L))

where V_(B) is the battery voltage, R is the resistance, t is the timeand L is the inductance, and generates the battery current curve basedon the above equation. The values for the resistance R and theinductance L are known and stored in the handle assembly 14. The aboveequation is representative of a charging current curve for an inductor(e.g., the motor). At t=0, the current I=0. As t approaches infinity,the current I=V_(B)/R. Third, given the measured battery current I, thecontrol system (e.g., the main processor 2006) determines the value ofV_(B). Fourth, the control system (e.g., the main processor 2006) alsodesignates the maximum value of the samples as the initial condition ofa recirculation current curve representative of the following equation:

I=(V _(B) /R)(e ^(−tR/L))

where V_(B) is the determined battery voltage value, R is theresistance, t is the time and L is the inductance, and generates therecirculation current curve based on the above equation. The values forthe resistance R and the inductance L are known and stored in the handleassembly 14. From this point, the control system (e.g., the mainprocessor 2006) determines the area under the battery current curve andthe area under the recirculation current curve. Next, the control system(e.g. the main processor) adds the areas under the battery current curveand the recirculation current curves to determine the average totalcurrent at the motor 3102. Finally, the determined average total currentat the motor 3102 may be input to or utilized by the main processor 2006to control the electric motor 3102, and by extension, to control a forceapplied to the drive system of the surgical stapler when the motor isoperating in the first or second direction.

According to yet other embodiments, in lieu of utilizing the measuredbattery current and the predicted recirculation current to control theelectric motor, the measured battery current and a state of a duty cycleassociated with a pulse width modulation circuit may be utilized tocontrol the electric motor, and by extension, to control a force appliedto the drive system of the surgical stapler when the electric motor isoperating in the first or second direction. For example, the measuredbattery current and the state of the duty cycle may be utilized in thefollowing manner.

First, during the manufacturing of the surgical stapler, the surgicalstapler is run at increments of PWM duty cycle between 0% and 100%. Ateach increment of the PWM duty cycle test, a range of loads are appliedto the surgical stapler and the current draw from the battery 3104 isalso measured. Also, at each increment of the PWM duty cycle test, themeasured current draw is tabulated against the PWM duty cycle and theassociated load. Based on the tests, a PWM and current versus forcelookup table is generated and stored in a memory (e.g., a nonvolatilememory) of the surgical stapler. Second, during the subsequent use ofthe surgical stapler, the control system of the surgical staplerutilizes pulse width modulation to modulate the voltage applied to themotor to achieve a target force applied by the surgical stapler. Toachieve the target force, the state of the PWM duty cycle (e.g., 20%,30%, etc.) and the value of the measured battery current are input tothe lookup table to obtain the actual force being applied by thesurgical stapler. Third, the control system compares the actual force totarget force and adjusts the PWM duty cycle to increase or decrease theactual force being applied by the surgical stapler as required toachieve the target force.

According to various embodiments, the PWM and current versus forcelookup table is stored in the main processor 2006. For surgical staplerswhich also include the safety processor 2004, the PWM and current versusforce lookup table can be passed to both the main processor 2006 and thesafety processor 2004 during manufacturing. For such embodiments, thePWM duty cycle can be communicated from the main processor 2006 to thesafety processor 2004 during the use of the surgical stapler. Accordingto other embodiments, the safety processor 2004 could measure the PWMsignal issuing from the main processor 2006 and decode it to access theappropriate force value in the PWM and current versus force lookuptable.

EXAMPLES Example 1

A surgical stapler is provided. The surgical stapler comprises a drivesystem, an electric motor mechanically coupled to the drive system, abattery electrically couplable to the electric motor, and a controlsystem electrically connected to the electric motor. The control systemcomprises an H-bridge circuit, an electrically resistive element, and anelectrically inductive element electrically connected to theelectrically resistive element. The H-bridge circuit comprises a highside and a low side, wherein the low side of the H-bridge circuitcomprises first and second switching devices. The electrically resistiveelement is electrically connected in series with the first switchingdevice. The control system is configured to control a force applied tothe drive system based on a current downstream of the electricallyresistive element.

Example 2

The surgical stapler of Example 1, wherein the low side of the H-bridgecircuit comprises first and second legs, and the electrically resistiveelement and the electrically inductive element are electricallyconnected to one of the first and second legs of the H-bridge circuit.

Example 3

The surgical stapler of Examples 1 or 2, wherein the electricallyinductive element is electrically connected in series with theelectrically resistive element.

Example 4

The surgical stapler of Examples 1 or 2, wherein the electricallyinductive element is electrically connected in parallel with theelectrically resistive element.

Example 5

The surgical stapler of Examples 1, 2 or 4, further comprising anelectrically capacitive element electrically connected in series withthe electrically inductive element.

Example 6

The surgical stapler of Examples 1, 2, 3, 4 or 5, further comprising, asecond electrically resistive element electrically connected in serieswith the second switching device, and a second electrically inductiveelement electrically connected to the second electrically resistiveelement, wherein the control system is further configured to control asecond force applied to the drive system based on a second currentmeasured downstream of the second electrically resistive element.

Example 7

The surgical stapler of Example 6, wherein the second electricallyinductive element is electrically connected in series with the secondelectrically resistive element.

Example 8

The surgical stapler of Example 6, wherein the second electricallyinductive element is electrically connected in parallel with the secondelectrically resistive element.

Example 9

The surgical stapler of Examples 6 or 8, further comprising a secondelectrically capacitive element electrically connected in series withthe second electrically inductive element.

Example 10

A surgical stapler is provided. The surgical stapler comprises a drivesystem, an electric motor mechanically coupled to the drive system, abattery electrically couplable to the electric motor, and a controlsystem electrically connected to the electric motor. The control systemcomprises an H-bridge circuit, an electrically inductive element, and afilter magnetically coupled to the electrically inductive element. TheH-bridge circuit comprises a high side and a low side, wherein the lowside of the H-bridge circuit comprises first and second switchingdevices. The electrically inductive element is electrically connected inseries with the first switching device. The control system is configuredto control a force applied to the drive system based on a current in thefilter.

Example 11

The surgical stapler of Example 10, wherein the filter comprises asecond electrically inductive element magnetically coupled to the firstelectrically inductive element, an electrically resistive elementelectrically connected to the second electrically inductive element, andan electrically capacitive element electrically connected to theelectrically resistive element.

Example 12

The surgical stapler of Examples 10 or 11, further comprising a sensorconfigured to sense the current in the filter.

Example 13

The surgical stapler of Examples 10, 11 or 12, further comprising athird electrically inductive element electrically connected in serieswith the second switching device, and a second filter magneticallycoupled to the third electrically inductive element, wherein the controlsystem is further configured to control a second force applied to thedrive system based on a second current in the second filter.

Example 14

The surgical stapler of Example 13, wherein the second filter comprisesa fourth electrically inductive element magnetically coupled to thethird electrically inductive element, a second electrically resistiveelement electrically connected to the fourth electrically inductiveelement, and a second electrically capacitive element electricallyconnected to the second electrically resistive element.

Example 15

The surgical stapler of Examples 12 or 13, further comprising a secondsensor configured to sense the second current in the filter.

Example 16

A surgical stapler is provided. The surgical stapler comprises a drivesystem, an electric motor mechanically coupled to the drive system, abattery electrically couplable to the electric motor, and a controlsystem electrically connected to the electric motor. The control systemcomprises a pulse width modulation circuit and is configured to controla force applied to the drive system based on, one, a plurality ofbattery current measurements taken while a pulse signal generated by thepulse modulation circuit is above a baseline value, and, two, aplurality of predicted recirculating current values, wherein thepredicted recirculating current values are based on at least one of theplurality of battery current measurements.

Example 17

The surgical stapler of Example 16, wherein the control system isfurther configured to fit the plurality of battery current measurementsto a first curve defined by a first mathematical equation, utilize aparameter of the first mathematical equation to predict a plurality ofrecirculating current values, fit the plurality of predictedrecirculating current values to a second curve defined by a secondmathematical equation, determine an intersection of the first and secondcurves, and determine a total area under the first and second curves.

Example 18

The surgical stapler of Example 17, wherein the total area under thefirst and second curves is representative of an average current at theelectric motor.

Example 19

The surgical stapler of Examples 16, 17 or 18, wherein the controlsystem is further configured to predict the recirculating current valuesbased on a maximum value of the plurality of battery currentmeasurements taken.

Example 20

The surgical stapler of claim 19, wherein the control system is furtherconfigured to determine the maximum value, designate the maximum valueas an ending condition of a battery current curve and as an initialcondition of a recirculation current curve, generate the battery currentcurve based on a first mathematical equation and generate recirculationcurrent curve based on a second mathematical equation, and determine atotal area under the battery current curve and the recirculation currentcurve.

Example 21

The surgical stapler of Example 20, wherein the total area under thebattery current curve and the recirculation current curve isrepresentative of an average current at the electric motor.

Example 22

A surgical stapler is provided. The surgical stapler comprises a drivesystem, an electric motor mechanically coupled to the drive system, abattery electrically couplable to the electric motor, and a controlsystem electrically connected to the electric motor. The control systemcomprises a pulse width modulation circuit and is configured to controla force applied to the drive system based on, one, a battery currentmeasurement taken while a pulse signal generated by the pulse modulationcircuit is above a baseline value, and, two, a state of a duty cycleassociated with the pulse width modulation circuit.

Example 23

The surgical stapler of Example 22, wherein the control system isfurther configured to read a force value from a look-up table of amemory of the surgical stapler based on the measured battery current andthe state of the duty cycle, compare the read force value to a targetforce value, and modify the duty cycle.

The entire disclosures of:

U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE,which issued on Apr. 4, 1995;

U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVINGSEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21,2006;

U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING ANDFASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued onSep. 9, 2008;

U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENTWITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec.16, 2008;

U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING ANARTICULATING END EFFECTOR, which issued on Mar. 2, 2010;

U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, whichissued on Jul. 13, 2010;

U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLEFASTENER CARTRIDGE, which issued on Mar. 12, 2013;

U.S. patent application Ser. No. 11/343,803, entitled SURGICALINSTRUMENT HAVING RECORDING CAPABILITIES; now U.S. Pat. No. 7,845,537;

U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTINGAND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008;

U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FORA SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, nowU.S. Pat. No. 7,980,443;

U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVENSURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411;

U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICALCUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM,now U.S. Pat. No. 8,608,045;

U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVENSURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROLASSEMBLY, filed Dec. 24, 2009; now U.S. Pat. No. 8,220,688;

U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE,filed Sep. 29, 2012, now U.S. Pat. No. 8,733,613;

U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLINGINSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870;

U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLINGINSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat.No. 9,072,535;

U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLESURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012;now U.S. Pat. No. 9,101,358;

U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGETISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Pat.No. 9,345,481;

U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGETISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. PatentApplication Publication No. 2014/0263552;

U.S. Patent Application Publication No. 2007/0175955, entitled SURGICALCUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM,filed Jan. 31, 2006; and

U.S. Patent Application Publication No. 2010/0264194, entitled SURGICALSTAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22,2010, now U.S. Pat. No. 8,308,040, are hereby incorporated by referenceherein.

Although the various embodiments of the devices have been describedherein in connection with certain disclosed embodiments, manymodifications and variations to those embodiments may be implemented.Also, where materials are disclosed for certain components, othermaterials may be used. Furthermore, according to various embodiments, asingle component may be replaced by multiple components, and multiplecomponents may be replaced by a single component, to perform a givenfunction or functions. The foregoing description and following claimsare intended to cover all such modification and variations.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

By way of example only, aspects described herein may be processed beforesurgery. First, a new or used instrument may be obtained and whennecessary cleaned. The instrument may then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK (commercially available from E. I.du Pont de Nemours and Company) bag. The container and instrument maythen be placed in a field of radiation that can penetrate the container,such as gamma radiation, x-rays, or high-energy electrons. The radiationmay kill bacteria on the instrument and in the container. The sterilizedinstrument may then be stored in the sterile container. The sealedcontainer may keep the instrument sterile until it is opened in amedical facility. A device also may be sterilized using any othertechnique known in the art, including but not limited to beta or gammaradiation, ethylene oxide, plasma peroxide, or steam.

While this invention has been described as having exemplary designs, thepresent invention may be further modified within the spirit and scope ofthe disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

1. A surgical stapler, comprising: a drive system; an electric motormechanically coupled to the drive system; a battery electricallycouplable to the electric motor; and a control system electricallyconnected to the electric motor, the control system comprising: anH-bridge circuit comprising a high side and a low side, wherein the lowside of the H-bridge circuit comprises first and second switchingdevices; an electrically resistive element electrically connected inseries with the first switching device; and an electrically inductiveelement electrically connected to the electrically resistive element,wherein the control system is configured to control a force applied tothe drive system based on a current downstream of the electricallyresistive element.
 2. The surgical stapler of claim 1, wherein: the lowside of the H-bridge circuit comprises first and second legs; and theelectrically resistive element and the electrically inductive elementare electrically connected to one of the first and second legs of theH-bridge circuit.
 3. The surgical stapler of claim 1, wherein theelectrically inductive element is electrically connected in series withthe electrically resistive element.
 4. The surgical stapler of claim 1,wherein the electrically inductive element is electrically connected inparallel with the electrically resistive element.
 5. The surgicalstapler of claim 4, further comprising an electrically capacitiveelement electrically connected in series with the electrically inductiveelement.
 6. The surgical stapler of claim 1, further comprising: asecond electrically resistive element electrically connected in serieswith the second switching device; and a second electrically inductiveelement electrically connected to the second electrically resistiveelement, wherein the control system is further configured to control asecond force applied to the drive system based on a second currentmeasured downstream of the second electrically resistive element.
 7. Thesurgical stapler of claim 6, wherein the second electrically inductiveelement is electrically connected in series with the second electricallyresistive element.
 8. The surgical stapler of claim 6, wherein thesecond electrically inductive element is electrically connected inparallel with the second electrically resistive element.
 9. The surgicalstapler of claim 8, further comprising a second electrically capacitiveelement electrically connected in series with the second electricallyinductive element.
 10. A surgical stapler, comprising: a drive system;an electric motor mechanically coupled to the drive system; a batteryelectrically couplable to the electric motor; and a control systemelectrically connected to the electric motor, the control systemcomprising: an H-bridge circuit comprising a high side and a low side,wherein the low side of the H-bridge circuit comprises first and secondswitching devices; an electrically inductive element electricallyconnected in series with the first switching device; and a filtermagnetically coupled to the electrically inductive element, wherein thecontrol system is configured to control a force applied to the drivesystem based on a current in the filter.
 11. The surgical stapler ofclaim 10, wherein the filter comprises: a second electrically inductiveelement magnetically coupled to the first electrically inductiveelement; an electrically resistive element electrically connected to thesecond electrically inductive element; and an electrically capacitiveelement electrically connected to the electrically resistive element.12. The surgical stapler of claim 10, further comprising a sensorconfigured to sense the current in the filter.
 13. The surgical staplerof claim 10, further comprising: a third electrically inductive elementelectrically connected in series with the second switching device; and asecond filter magnetically coupled to the third electrically inductiveelement, wherein the control system is further configured to control asecond force applied to the drive system based on a second current inthe second filter.
 14. The surgical stapler of claim 13, wherein thesecond filter comprises: a fourth electrically inductive elementmagnetically coupled to the third electrically inductive element; asecond electrically resistive element electrically connected to thefourth electrically inductive element; and a second electricallycapacitive element electrically connected to the second electricallyresistive element.
 15. The surgical stapler of claim 13, furthercomprising a second sensor configured to sense the second current in thefilter.
 16. A surgical stapler, comprising: a drive system; an electricmotor mechanically coupled to the drive system; a battery electricallycouplable to the electric motor; and a control system electricallyconnected to the electric motor, wherein the control system comprises apulse width modulation circuit and is configured to control a forceapplied to the drive system based on: a plurality of battery currentmeasurements taken while a pulse signal generated by the pulsemodulation circuit is above a baseline value; and a plurality ofpredicted recirculating current values, wherein the predictedrecirculating current values are based on at least one of the pluralityof battery current measurements.
 17. The surgical stapler of claim 16,wherein the control system is further configured to: fit the pluralityof battery current measurements to a first curve defined by a firstmathematical equation; utilize a parameter of the first mathematicalequation to predict a plurality of recirculating current values; fit theplurality of predicted recirculating current values to a second curvedefined by a second mathematical equation; determine an intersection ofthe first and second curves; and determine a total area under the firstand second curves.
 18. The surgical stapler of claim 17, wherein thetotal area under the first and second curves is representative of anaverage current at the electric motor.
 19. The surgical stapler of claim16, wherein the control system is further configured to predict therecirculating current values based on a maximum value of the pluralityof battery current measurements taken.
 20. The surgical stapler of claim19, wherein the control system is further configured to: determine themaximum value; designate the maximum value as an ending condition of abattery current curve and as an initial condition of a recirculationcurrent curve; generate the battery current curve based on a firstmathematical equation and generate recirculation current curve based ona second mathematical equation; and determine a total area under thebattery current curve and the recirculation current curve. 21-23.(canceled)